diff --git a/modules/common/math/BUILD b/modules/common/math/BUILD
index 65b59458b786120a49c07c4ff1e88b0dc0ed4a5e..37817d035752fd304d7f4f777295c31443f629bd 100644
--- a/modules/common/math/BUILD
+++ b/modules/common/math/BUILD
@@ -49,6 +49,7 @@ cc_library(
     ],
     deps = [
         "//modules/common:log",
+        "//modules/common/util:string_util",
     ],
 )
 
@@ -165,6 +166,7 @@ cc_library(
     deps = [
         "//modules/common:log",
         "//modules/common/math:matrix_operations",
+        "//modules/common/util:string_util",
         "@eigen//:eigen",
     ],
 )
diff --git a/modules/common/math/aabox2d.cc b/modules/common/math/aabox2d.cc
index c70c5320c019fb193ff40d63fcae3f58b881dadd..486c53e3344edac792a59fed99cd99f528f9e6ce 100644
--- a/modules/common/math/aabox2d.cc
+++ b/modules/common/math/aabox2d.cc
@@ -18,9 +18,9 @@
 
 #include <algorithm>
 #include <cmath>
-#include <sstream>
 
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 #include "modules/common/math/math_utils.h"
 
@@ -146,11 +146,9 @@ void AABox2d::MergeFrom(const Vec2d &other_point) {
 }
 
 std::string AABox2d::DebugString() const {
-  std::ostringstream sout;
-  sout << "aabox2d ( center = " << center_.DebugString()
-       << "  length = " << length_ << "  width = " << width_ << " )";
-  sout.flush();
-  return sout.str();
+  return util::StrCat(
+      "aabox2d ( center = ", center_.DebugString(),
+      "  length = ", length_, "  width = ", width_, " )");
 }
 
 }  // namespace math
diff --git a/modules/common/math/box2d.cc b/modules/common/math/box2d.cc
index cd59db22396c1db035dff6089b30e759d508e881..87f867f6b127d9e4641657df774ac17bfdbd3c18 100644
--- a/modules/common/math/box2d.cc
+++ b/modules/common/math/box2d.cc
@@ -18,10 +18,10 @@
 
 #include <algorithm>
 #include <cmath>
-#include <sstream>
 #include <utility>
 
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 #include "modules/common/math/math_utils.h"
 #include "modules/common/math/polygon2d.h"
@@ -303,12 +303,10 @@ void Box2d::RotateFromCenter(const double rotate_angle) {
 void Box2d::Shift(const Vec2d &shift_vec) { center_ += shift_vec; }
 
 std::string Box2d::DebugString() const {
-  std::ostringstream sout;
-  sout << "box2d ( center = " << center_.DebugString()
-       << "  heading = " << heading_ << "  length = " << length_
-       << "  width = " << width_ << " )";
-  sout.flush();
-  return sout.str();
+  return util::StrCat(
+      "box2d ( center = ", center_.DebugString(),
+      "  heading = ", heading_, "  length = ", length_,
+      "  width = ", width_, " )");
 }
 
 }  // namespace math
diff --git a/modules/common/math/kalman_filter.h b/modules/common/math/kalman_filter.h
index 068281a7b8f8873bdbd46d36bc84fb0b112087d2..361a3f207d80246bc17d78c8740be8226e9bc8f8 100644
--- a/modules/common/math/kalman_filter.h
+++ b/modules/common/math/kalman_filter.h
@@ -22,13 +22,13 @@
 #ifndef MODULES_COMMON_MATH_KALMAN_FILTER_H_
 #define MODULES_COMMON_MATH_KALMAN_FILTER_H_
 
-#include <sstream>
 #include <string>
 
 #include "Eigen/Dense"
 
 #include "modules/common/log.h"
 #include "modules/common/math/matrix_operations.h"
+#include "modules/common/util/string_util.h"
 
 /**
  * @namespace apollo::common::math
@@ -266,15 +266,14 @@ inline void KalmanFilter<T, XN, ZN, UN>::Correct(
 template <typename T, unsigned int XN, unsigned int ZN, unsigned int UN>
 inline std::string KalmanFilter<T, XN, ZN, UN>::DebugString() const {
   Eigen::IOFormat clean_fmt(4, 0, ", ", " ", "[", "]");
-  std::ostringstream strs;
-  strs << "F = " << F_.format(clean_fmt) << "\n";
-  strs << "B = " << B_.format(clean_fmt) << "\n";
-  strs << "H = " << H_.format(clean_fmt) << "\n";
-  strs << "Q = " << Q_.format(clean_fmt) << "\n";
-  strs << "R = " << R_.format(clean_fmt) << "\n";
-  strs << "x = " << x_.format(clean_fmt) << "\n";
-  strs << "P = " << P_.format(clean_fmt) << "\n";
-  return strs.str();
+  return util::StrCat(
+      "F = ", F_.format(clean_fmt), "\n"
+      "B = ", B_.format(clean_fmt), "\n"
+      "H = ", H_.format(clean_fmt), "\n"
+      "Q = ", Q_.format(clean_fmt), "\n"
+      "R = ", R_.format(clean_fmt), "\n"
+      "x = ", x_.format(clean_fmt), "\n"
+      "P = ", P_.format(clean_fmt), "\n");
 }
 
 }  // namespace math
diff --git a/modules/common/math/line_segment2d.cc b/modules/common/math/line_segment2d.cc
index a1ccaaedb7349bd8fb83dc491916ef165ba9f1fa..10b6b37a4619e410023c2d4279dcfcb3c09ae110 100644
--- a/modules/common/math/line_segment2d.cc
+++ b/modules/common/math/line_segment2d.cc
@@ -18,10 +18,10 @@
 
 #include <algorithm>
 #include <cmath>
-#include <sstream>
 #include <utility>
 
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 #include "modules/common/math/math_utils.h"
 
@@ -214,11 +214,8 @@ double LineSegment2d::GetPerpendicularFoot(const Vec2d &point,
 }
 
 std::string LineSegment2d::DebugString() const {
-  std::ostringstream sout;
-  sout << "segment2d ( start = " << start_.DebugString()
-       << "  end = " << end_.DebugString() << " )";
-  sout.flush();
-  return sout.str();
+  return util::StrCat("segment2d ( start = ", start_.DebugString(),
+                      "  end = ", end_.DebugString(), " )");
 }
 
 }  // namespace math
diff --git a/modules/common/math/vec2d.cc b/modules/common/math/vec2d.cc
index 9f71b8633661f1b182a10ba0c96fcac94b47e20a..f0fad1d8dde61e04bd8ff834dc5e07efbbefc2bc 100644
--- a/modules/common/math/vec2d.cc
+++ b/modules/common/math/vec2d.cc
@@ -17,8 +17,9 @@
 #include "modules/common/math/vec2d.h"
 
 #include <cmath>
-#include <sstream>
+
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 namespace apollo {
 namespace common {
@@ -110,10 +111,7 @@ bool Vec2d::operator==(const Vec2d &other) const {
 Vec2d operator*(const double ratio, const Vec2d &vec) { return vec * ratio; }
 
 std::string Vec2d::DebugString() const {
-  std::ostringstream sout;
-  sout << "vec2d ( x = " << x_ << "  y = " << y_ << " )";
-  sout.flush();
-  return sout.str();
+  return util::StrCat("vec2d ( x = ", x_, "  y = ", y_, " )");
 }
 
 }  // namespace math
diff --git a/modules/common/util/BUILD b/modules/common/util/BUILD
index bb27685879e9ab801a0ab23b0cd71e34eefd50e9..6ca71e284db2ef136e29bb4cfc07401c59cc1663 100644
--- a/modules/common/util/BUILD
+++ b/modules/common/util/BUILD
@@ -26,14 +26,24 @@ cc_library(
     hdrs = ["lru_cache.h"],
 )
 
+cc_library(
+    name = "string_util",
+    srcs = [
+        "string_util.cc",
+    ],
+    hdrs = [
+        "string_util.h",
+    ],
+)
+
 cc_test(
-    name = "util_test",
+    name = "string_util_test",
     size = "small",
     srcs = [
-        "util_test.cc",
+        "string_util_test.cc",
     ],
     deps = [
-        ":util",
+        ":string_util",
         "@gtest//:main",
     ],
 )
diff --git a/modules/common/util/file.h b/modules/common/util/file.h
index bf34b8a2aa3511f54cd704a1103a87556f91e59a..3de2433d84a5d5ca7cc1f5ff96742562cb2e41e0 100644
--- a/modules/common/util/file.h
+++ b/modules/common/util/file.h
@@ -32,7 +32,7 @@
 #include "google/protobuf/io/zero_copy_stream_impl.h"
 #include "google/protobuf/text_format.h"
 #include "modules/common/log.h"
-#include "modules/common/util/util.h"
+#include "modules/common/util/string_util.h"
 
 /**
  * @namespace apollo::common::util
diff --git a/modules/common/util/string_util.cc b/modules/common/util/string_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..151e23965c588c8e936484d598a5dfef89f2928b
--- /dev/null
+++ b/modules/common/util/string_util.cc
@@ -0,0 +1,30 @@
+/******************************************************************************
+ * Copyright 2017 The Apollo Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *****************************************************************************/
+
+#include "modules/common/util/string_util.h"
+
+namespace apollo {
+namespace common {
+namespace util {
+
+bool EndWith(const std::string& original, const std::string& pattern) {
+  return original.length() >= pattern.length() &&
+         original.substr(original.length() - pattern.length()) == pattern;
+}
+
+}  // namespace util
+}  // namespace common
+}  // namespace apollo
diff --git a/modules/common/util/string_util.h b/modules/common/util/string_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..a3ddc18fc688fab3d199482808011a11af660737
--- /dev/null
+++ b/modules/common/util/string_util.h
@@ -0,0 +1,62 @@
+/******************************************************************************
+ * Copyright 2017 The Apollo Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *****************************************************************************/
+
+/**
+ * @file
+ * @brief Some string util functions.
+ */
+
+#ifndef MODULES_COMMON_STRING_UTIL_H_
+#define MODULES_COMMON_STRING_UTIL_H_
+
+#include <sstream>
+#include <string>
+
+/**
+ * @namespace apollo::common::util
+ * @brief apollo::common::util
+ */
+namespace apollo {
+namespace common {
+namespace util {
+
+/**
+ * @brief Check if a string ends with a pattern.
+ * @param original The original string. To see if it ends with some
+ *        specified pattern.
+ * @param pattern The target pattern. To see if the original string ends
+ *        with it.
+ * @return Whether the original string ends with the specified pattern.
+ */
+bool EndWith(const std::string& original, const std::string& pattern);
+
+/**
+ * @brief Concat parameters to a string, e.g.: StrCat("age = ", 32)
+ * @return String of concated parameters.
+ */
+template <typename ...T>
+std::string StrCat(const T& ...args) {
+  std::ostringstream oss;
+  // Expand args and pass to oss.
+  std::initializer_list<char>{(oss << args, ' ') ... };
+  return oss.str();
+}
+
+}  // namespace util
+}  // namespace common
+}  // namespace apollo
+
+#endif  // MODULES_COMMON_STRING_UTIL_H_
diff --git a/modules/common/util/util_test.cc b/modules/common/util/string_util_test.cc
similarity index 96%
rename from modules/common/util/util_test.cc
rename to modules/common/util/string_util_test.cc
index 453b47c810508faf5d34fe0209746acfc6597bb2..298dc7957fd9a90984bae4db2ac57cbdf6c82abc 100644
--- a/modules/common/util/util_test.cc
+++ b/modules/common/util/string_util_test.cc
@@ -14,7 +14,8 @@
  * limitations under the License.
  *****************************************************************************/
 
-#include "modules/common/util/util.h"
+#include "modules/common/util/string_util.h"
+
 #include "gtest/gtest.h"
 
 namespace apollo {
diff --git a/modules/common/util/util.cc b/modules/common/util/util.cc
index b9408917f7ade23dd94dd4cd22c9598e96927efd..a5a75c42408124d20028547b5bae8bbc9f5fb3e6 100644
--- a/modules/common/util/util.cc
+++ b/modules/common/util/util.cc
@@ -24,11 +24,6 @@ namespace util {
 
 using SLPoint = apollo::common::SLPoint;
 
-bool EndWith(const std::string& original, const std::string& pattern) {
-  return original.length() >= pattern.length() &&
-         original.substr(original.length() - pattern.length()) == pattern;
-}
-
 SLPoint MakeSLPoint(const double s, const double l) {
   SLPoint sl;
   sl.set_s(s);
diff --git a/modules/common/util/util.h b/modules/common/util/util.h
index 8dd855996936f5e3f1633c0aa0b99f916a92cb84..8d330e2a9b6d346ad62185b969c4169db53e3be7 100644
--- a/modules/common/util/util.h
+++ b/modules/common/util/util.h
@@ -23,8 +23,6 @@
 #define MODULES_COMMON_UTIL_H_
 
 #include <iostream>
-#include <string>
-#include <sstream>
 #include <utility>
 
 #include "modules/common/proto/path_point.pb.h"
@@ -37,28 +35,6 @@ namespace apollo {
 namespace common {
 namespace util {
 
-/**
- * @brief Check if a string ends with a pattern.
- * @param original The original string. To see if it ends with some
- *        specified pattern.
- * @param pattern The target pattern. To see if the original string ends
- *        with it.
- * @return Whether the original string ends with the specified pattern.
- */
-bool EndWith(const std::string& original, const std::string& pattern);
-
-/**
- * @brief Concat parameters to a string, e.g.: StrCat("age = ", 32)
- * @return String of concated parameters.
- */
-template <typename ...T>
-std::string StrCat(const T& ...args) {
-  std::ostringstream oss;
-  // Expand args and pass to oss.
-  std::initializer_list<char>{(oss << args, ' ') ... };
-  return oss.str();
-}
-
 /**
  * @brief create a SL point
  * @param s the s value
diff --git a/modules/control/controller/lat_controller.cc b/modules/control/controller/lat_controller.cc
index e50d30b1905f6639ade2cd7f62df5b5beb7f63b8..cabe79b67fb111ad81e3502016c239bd2d973746 100644
--- a/modules/control/controller/lat_controller.cc
+++ b/modules/control/controller/lat_controller.cc
@@ -19,7 +19,6 @@
 #include <algorithm>
 #include <cmath>
 #include <iomanip>
-#include <sstream>
 #include <string>
 #include <utility>
 #include <vector>
@@ -30,6 +29,7 @@
 #include "modules/common/math/linear_quadratic_regulator.h"
 #include "modules/common/math/math_utils.h"
 #include "modules/common/time/time.h"
+#include "modules/common/util/string_util.h"
 #include "modules/control/common/control_gflags.h"
 
 namespace apollo {
@@ -119,24 +119,27 @@ bool LatController::LoadControlConf(const ControlConf *control_conf) {
 
 void LatController::ProcessLogs(const SimpleLateralDebug *debug,
                                 const canbus::Chassis *chassis) {
-  std::stringstream log_stream;
-  log_stream << debug->lateral_error() << "," << debug->ref_heading() << ","
-             << VehicleState::instance()->heading() << ","
-             << debug->heading_error() << "," << debug->heading_error_rate()
-             << "," << debug->lateral_error_rate() << "," << debug->curvature()
-             << "," << debug->steer_angle() << ","
-             << debug->steer_angle_feedforward() << ","
-             << debug->steer_angle_lateral_contribution() << ","
-             << debug->steer_angle_lateral_rate_contribution() << ","
-             << debug->steer_angle_heading_contribution() << ","
-             << debug->steer_angle_heading_rate_contribution() << ","
-             << debug->steer_angle_feedback() << ","
-             << chassis->steering_percentage() << ","
-             << VehicleState::instance()->linear_velocity();
+  const std::string log_str = apollo::common::util::StrCat(
+      debug->lateral_error(), ",",
+      debug->ref_heading(), ",",
+      VehicleState::instance()->heading(), ",",
+      debug->heading_error(), ",",
+      debug->heading_error_rate(), ",",
+      debug->lateral_error_rate(), ",",
+      debug->curvature(), ",",
+      debug->steer_angle(), ",",
+      debug->steer_angle_feedforward(), ",",
+      debug->steer_angle_lateral_contribution(), ",",
+      debug->steer_angle_lateral_rate_contribution(), ",",
+      debug->steer_angle_heading_contribution(), ",",
+      debug->steer_angle_heading_rate_contribution(), ",",
+      debug->steer_angle_feedback(), ",",
+      chassis->steering_percentage(), ",",
+      VehicleState::instance()->linear_velocity());
   if (FLAGS_enable_csv_debug) {
-    steer_log_file_ << log_stream.str() << std::endl;
+    steer_log_file_ << log_str << std::endl;
   }
-  AINFO << "Steer_Control_Detail: " << log_stream.str();
+  AINFO << "Steer_Control_Detail: " << log_str;
 }
 
 void LatController::LogInitParameters() {
diff --git a/modules/dreamview/backend/websocket/BUILD b/modules/dreamview/backend/websocket/BUILD
index 060627f488da72b8d47a17b06cce6df7001682dc..503058229a04a55632738a956f1d05c00f9675d4 100644
--- a/modules/dreamview/backend/websocket/BUILD
+++ b/modules/dreamview/backend/websocket/BUILD
@@ -12,6 +12,7 @@ cc_library(
     ],
     deps = [
         "//modules/common:log",
+        "//modules/common/util:string_util",
         "//third_party/json",
         "@civetweb//:civetweb++",
     ],
diff --git a/modules/dreamview/backend/websocket/websocket.cc b/modules/dreamview/backend/websocket/websocket.cc
index dfc45d1629a2ad8f8a6fbd543a2a6289278b2721..f476468b886e53c31d067ed240878d8afcbacbfa 100644
--- a/modules/dreamview/backend/websocket/websocket.cc
+++ b/modules/dreamview/backend/websocket/websocket.cc
@@ -15,10 +15,10 @@ limitations under the License.
 
 #include "modules/dreamview/backend/websocket/websocket.h"
 
-#include <sstream>
 #include <vector>
 
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 namespace apollo {
 namespace dreamview {
@@ -74,13 +74,10 @@ bool WebSocketHandler::SendData(const std::string &data, Connection *conn) {
     } else if (ret < 0) {
       msg = "Send Error";
     } else {
-      std::ostringstream os;
-      os << "Expect to send " << data.size() << " bytes. But sent " << ret
-         << " bytes";
-      msg = os.str();
+      msg = apollo::common::util::StrCat(
+          "Expect to send ", data.size(), " bytes. But sent ", ret, " bytes");
     }
-    AWARN << "Failed to send data via websocket connection. Reason: "
-                 << msg;
+    AWARN << "Failed to send data via websocket connection. Reason: " << msg;
     return false;
   }
 
diff --git a/modules/map/pnc_map/path.cc b/modules/map/pnc_map/path.cc
index 6c118920af3e8198c5a9ea5e75b60d1e934b8a14..3f547134bd00690bd2826579db30394dfe1bfafc 100644
--- a/modules/map/pnc_map/path.cc
+++ b/modules/map/pnc_map/path.cc
@@ -25,6 +25,7 @@
 #include "modules/common/math/math_utils.h"
 #include "modules/common/math/polygon2d.h"
 #include "modules/common/math/vec2d.h"
+#include "modules/common/util/string_util.h"
 
 namespace apollo {
 namespace hdmap {
@@ -60,21 +61,17 @@ std::string LaneWaypoint::debug_string() const {
   if (lane == nullptr) {
     return "(lane is null)";
   }
-  std::ostringstream sout;
-  sout << "id = " << lane->id().id() << "  s = " << s;
-  sout.flush();
-  return sout.str();
+  return apollo::common::util::StrCat("id = ", lane->id().id(), "  s = ", s);
 }
 
 std::string LaneSegment::debug_string() const {
   if (lane == nullptr) {
     return "(lane is null)";
   }
-  std::ostringstream sout;
-  sout << "id = " << lane->id().id() << "  start_s = " << start_s
-       << "  end_s = " << end_s;
-  sout.flush();
-  return sout.str();
+  return apollo::common::util::StrCat(
+      "id = ", lane->id().id(), "  "
+      "start_s = ", start_s, "  "
+      "end_s = ", end_s);
 }
 
 std::string MapPathPoint::debug_string() const {
@@ -121,10 +118,7 @@ std::string Path::debug_string() const {
 }
 
 std::string PathOverlap::debug_string() const {
-  std::ostringstream sout;
-  sout << object_id << " " << start_s << " " << end_s;
-  sout.flush();
-  return sout.str();
+  return apollo::common::util::StrCat(object_id, " ", start_s, " ", end_s);
 }
 
 Path::Path(std::vector<MapPathPoint> path_points)
diff --git a/modules/monitor/hwmonitor/hw/esdcan/esdcan_checker.cc b/modules/monitor/hwmonitor/hw/esdcan/esdcan_checker.cc
index a1a7e1057c275287bbe13ab831c978ee364cde69..f52303d78ca0626c02baa7b6cf34ebedaf488418 100644
--- a/modules/monitor/hwmonitor/hw/esdcan/esdcan_checker.cc
+++ b/modules/monitor/hwmonitor/hw/esdcan/esdcan_checker.cc
@@ -16,10 +16,10 @@
 
 #include "modules/monitor/hwmonitor/hw/esdcan/esdcan_checker.h"
 
-#include <sstream>
 #include <utility>
 #include <vector>
 
+#include "modules/common/util/string_util.h"
 #include "modules/monitor/hwmonitor/hw/esdcan/esdcan_err_str.h"
 #include "modules/monitor/hwmonitor/hw/hw_log_module.h"
 
@@ -30,9 +30,7 @@ namespace hw {
 const char EsdCanChecker::ESD_CAN_NAME[] = "ESD_CAN";
 
 EsdCanChecker::EsdCanChecker(int id) : can_id_(id) {
-  std::ostringstream os;
-  os << ESD_CAN_NAME << "-" << id;
-  name_ = os.str();
+  name_ = apollo::common::util::StrCat(ESD_CAN_NAME, "-", id);
 }
 
 hw::Status EsdCanChecker::esdcan_result_to_hw_status(NTCAN_RESULT ntstatus) {
diff --git a/modules/perception/obstacle/base/BUILD b/modules/perception/obstacle/base/BUILD
index d3a38acafb5ad73fc166aded8825c2941eed9191..7b21366b87a86ff56084cb6682f71fafa1c08460 100644
--- a/modules/perception/obstacle/base/BUILD
+++ b/modules/perception/obstacle/base/BUILD
@@ -11,6 +11,7 @@ cc_library(
         "//modules/perception/common:perception_common",
         "//modules/perception/proto:perception_proto",
         "//modules/common:common",
+        "//modules/common/util:string_util",
         "@eigen//:eigen",
     ],
 )
diff --git a/modules/perception/obstacle/base/object.cc b/modules/perception/obstacle/base/object.cc
index fde41aa3ad95b04afddd707f31f402f3e993b0e9..2ce50fb48fb86cdb6d40aae1c02e744afefc5808 100644
--- a/modules/perception/obstacle/base/object.cc
+++ b/modules/perception/obstacle/base/object.cc
@@ -15,15 +15,13 @@
  *****************************************************************************/
 #include "modules/perception/obstacle/base/object.h"
 
-#include <sstream>
-
 #include "modules/common/macro.h"
 #include "modules/common/log.h"
+#include "modules/common/util/string_util.h"
 
 namespace apollo {
 namespace perception {
 
-using std::ostringstream;
 using std::string;
 using std::vector;
 using Eigen::Vector3d;
@@ -95,18 +93,21 @@ void Object::clone(const Object& rhs) {
 }
 
 string Object::to_string() const {
-  ostringstream oss;
-  oss << "Object[id: " << id << ", track_id: " << track_id
-    << ", cloud_size: " << cloud->size() << ", direction: "
-    << direction.transpose() << ", center: " << center.transpose()
-    << " velocity: " << velocity.transpose() << ", width: " << width
-    << ", length: " << length << ", height: " << height
-    << ", polygon_size: " << polygon.size()
-    << ", type: " << type << ", is_background: " << is_background << "]";
-    // << ", tracking_time: " << GLOG_TIMESTAMP(tracking_time)
-    // << ", latest_tracked_time: " << GLOG_TIMESTAMP(latest_tracked_time) << "]";
-
-  return oss.str();
+  return apollo::common::util::StrCat(
+      "Object[id: ", id, ", "
+      "track_id: ", track_id, ", "
+      "cloud_size: ", cloud->size(), ", "
+      "direction: ", direction.transpose(), ", "
+      "center: ", center.transpose(), ", "
+      "velocity: ", velocity.transpose(), ", "
+      "width: ", width, ", "
+      "length: ", length, ", "
+      "height: ", height, ", "
+      "polygon_size: ", polygon.size(), ", "
+      "type: ", type, ", "
+      "is_background: ", is_background, "]");
+  // "tracking_time: ", GLOG_TIMESTAMP(tracking_time)
+  // "latest_tracked_time: ", GLOG_TIMESTAMP(latest_tracked_time)
 }
 
 bool Object::serialize(PerceptionObstacle* pb_obj) const {
diff --git a/modules/planning/common/speed/st_point.cc b/modules/planning/common/speed/st_point.cc
index ded98f548d927b5e5430afb62690518d7f1a6e95..20972cd8a4b87521630c7f0ed52640284786fda1 100644
--- a/modules/planning/common/speed/st_point.cc
+++ b/modules/planning/common/speed/st_point.cc
@@ -21,7 +21,8 @@
 #include "modules/planning/common/speed/st_point.h"
 
 #include <iomanip>
-#include <sstream>
+
+#include "modules/common/util/string_util.h"
 
 namespace apollo {
 namespace planning {
@@ -37,10 +38,9 @@ void STPoint::set_s(const double s) { return set_y(s); }
 void STPoint::set_t(const double t) { return set_x(t); }
 
 std::string STPoint::DebugString() const {
-  std::ostringstream sout;
-  sout << "{ \"s\" : " << std::setprecision(6) << s()
-       << ", \"t\" : " << std::setprecision(6) << t() << " }";
-  return sout.str();
+  return apollo::common::util::StrCat(
+      "{ \"s\" : ", std::setprecision(6), s(), ", "
+      "\"t\" : ", std::setprecision(6), t(), " }");
 }
 
 }  // namespace planning
diff --git a/modules/planning/reference_line/reference_point.cc b/modules/planning/reference_line/reference_point.cc
index 74f510699540ad1192454bdf3b74ddcaf9b7ae6c..c5614a948cfcc61a6fcd69a0ca763520268b21c0 100644
--- a/modules/planning/reference_line/reference_point.cc
+++ b/modules/planning/reference_line/reference_point.cc
@@ -21,6 +21,7 @@
 #include <string>
 #include <vector>
 
+#include "modules/common/util/string_util.h"
 #include "modules/planning/reference_line/reference_point.h"
 
 namespace apollo {
@@ -77,12 +78,14 @@ double ReferencePoint::lower_bound() const { return lower_bound_; }
 double ReferencePoint::upper_bound() const { return upper_bound_; }
 
 const std::string ReferencePoint::DebugString() const {
-  std::stringstream ss;
-  ss << "{x: " << std::fixed << x() << ", y: " << y() << ", theta: " << heading()
-     << ", kappa: " << kappa() << ", dkappa: " << dkappa()
-     << ", upper_bound: " << upper_bound() << ", lower_bound: " << lower_bound()
-     << "}";
-  return ss.str();
+  return apollo::common::util::StrCat(
+      "{x: ", std::fixed, x(), ", "
+      "y: ", y(), ", "
+      "theta: ", heading(), ", "
+      "kappa: ", kappa(), ", "
+      "dkappa: ", dkappa(), ", "
+      "upper_bound: ", upper_bound(), ", "
+      "lower_bound: ", lower_bound(), "}");
 }
 
 }  // namespace planning