diff --git a/paddle/framework/op_registry.h b/paddle/framework/op_registry.h
index bdaa25918155caca4b64b0ed60aa3f6be03eb12f..d75c0233e8e0134ddf4edc50c07490a234b65cd0 100644
--- a/paddle/framework/op_registry.h
+++ b/paddle/framework/op_registry.h
@@ -37,8 +37,8 @@ class Registrar {
  public:
   // In our design, various kinds of classes, e.g., operators and kernels,
   // have their corresponding registry and registrar. The action of
-  // registration is in the constructor of a global registrar variable, which,
-  // however, are not used in the code that calls package framework, and would
+  // registration is in the constructor of a global registrar variable, which
+  // are not used in the code that calls package framework, and would
   // be removed from the generated binary file by the linker. To avoid such
   // removal, we add Touch to all registrar classes and make USE_OP macros to
   // call this method. So, as long as the callee code calls USE_OP, the global
diff --git a/paddle/operators/CMakeLists.txt b/paddle/operators/CMakeLists.txt
index a0b61640e5bfdd62cbede786094fe5f8166ac483..77b52eb1760c7b79aa47efb447a4c99b6ab5e027 100644
--- a/paddle/operators/CMakeLists.txt
+++ b/paddle/operators/CMakeLists.txt
@@ -68,9 +68,10 @@ function(op_library TARGET)
         endif()
     endforeach()
 
+    # The registration of USE_OP, please refer to paddle/framework/op_registry.h.
+    # Note that it's enough to just adding one operator to pybind in a *_op.cc file.
+    # And for detail pybind information, please see generated paddle/pybind/pybind.h.
     file(READ ${TARGET}.cc TARGET_CONTENT)
-    # It's enough to just adding one operator to pybind.
-    # And for detail pybind information, please see paddle/pybind/pybind.h.
     string(REGEX MATCH "REGISTER_OP\\(.*REGISTER_OP\\(" multi_register "${TARGET_CONTENT}")
     string(REGEX MATCH "REGISTER_OP\\([a-z0-9_]*," one_register "${multi_register}")
     if (one_register STREQUAL "")