diff --git a/lite/demo/cxx/mask_detection/mask_detection.cc b/lite/demo/cxx/mask_detection/mask_detection.cc
index 27cabdd808c87de5ac041cec9c7fd482f8f098e0..09a9c0ee158e7d5913a78877711d831fc5738cf1 100644
--- a/lite/demo/cxx/mask_detection/mask_detection.cc
+++ b/lite/demo/cxx/mask_detection/mask_detection.cc
@@ -241,7 +241,7 @@ void RunModel(std::string det_model_file,
       roi_color = cv::Scalar(0, 0, 255);
       prob = 1 - prob;
     }
-    std::string prob_str = paddle::lite::to_string(prob * 100);
+    std::string prob_str = std::to_string(prob * 100);
     int point_idx = prob_str.find_last_of(".");
 
     text += prob_str.substr(0, point_idx + 3) + "%";
diff --git a/lite/demo/cxx/mobile_light/mobilenetv1_light_api.cc b/lite/demo/cxx/mobile_light/mobilenetv1_light_api.cc
index 6f900850557d5545a6de8e4cc7ba983e589dd5f1..150bcd231c27c25d8510fc8dfa3281a8351514dd 100644
--- a/lite/demo/cxx/mobile_light/mobilenetv1_light_api.cc
+++ b/lite/demo/cxx/mobile_light/mobilenetv1_light_api.cc
@@ -32,7 +32,7 @@ int64_t ShapeProduction(const shape_t& shape) {
 std::string ShapePrint(const shape_t& shape) {
   std::string shape_str{""};
   for (auto i : shape) {
-    shape_str += paddle::lite::to_string(i) + " ";
+    shape_str += std::to_string(i) + " ";
   }
   return shape_str;
 }
diff --git a/lite/demo/cxx/ssd_detection/ssd_detection.cc b/lite/demo/cxx/ssd_detection/ssd_detection.cc
index e5f815affbbe8e777760f08668719bd89527b37d..0be4561cd8d083f26e562c2346da217bb4b48283 100644
--- a/lite/demo/cxx/ssd_detection/ssd_detection.cc
+++ b/lite/demo/cxx/ssd_detection/ssd_detection.cc
@@ -126,7 +126,7 @@ std::vector<Object> detect_object(const float* data,
       if (w > 0 && h > 0 && obj.prob <= 1) {
         rect_out.push_back(obj);
         cv::rectangle(image, rec_clip, cv::Scalar(0, 0, 255), 2, cv::LINE_AA);
-        std::string str_prob = paddle::lite::to_string(obj.prob);
+        std::string str_prob = std::to_string(obj.prob);
         std::string text = std::string(class_names[obj.class_id]) + ": " +
                            str_prob.substr(0, str_prob.find(".") + 4);
         int font_face = cv::FONT_HERSHEY_COMPLEX_SMALL;
diff --git a/lite/demo/cxx/yolov3_detection/yolov3_detection.cc b/lite/demo/cxx/yolov3_detection/yolov3_detection.cc
index d488643f5a6599af4d8dba9e12f21bceed2c8029..d34319050392c74c3fa552bd24c0ea24245ced99 100644
--- a/lite/demo/cxx/yolov3_detection/yolov3_detection.cc
+++ b/lite/demo/cxx/yolov3_detection/yolov3_detection.cc
@@ -146,7 +146,7 @@ std::vector<Object> detect_object(const float* data,
       if (w > 0 && h > 0 && obj.prob <= 1) {
         rect_out.push_back(obj);
         cv::rectangle(image, rec_clip, cv::Scalar(0, 0, 255), 1, cv::LINE_AA);
-        std::string str_prob = paddle::lite::to_string(obj.prob);
+        std::string str_prob = std::to_string(obj.prob);
         std::string text = std::string(class_names[obj.class_id]) + ": " +
                            str_prob.substr(0, str_prob.find(".") + 4);
         int font_face = cv::FONT_HERSHEY_COMPLEX_SMALL;