diff --git a/cocos/ui/UIText.cpp b/cocos/ui/UIText.cpp
index 77f7d18cf2..ba9806f12e 100644
--- a/cocos/ui/UIText.cpp
+++ b/cocos/ui/UIText.cpp
@@ -115,7 +115,7 @@ const std::string& Text::getString() const
     return _labelRenderer->getString();
 }
 
-ssize_t Text::getStringLength()
+ssize_t Text::getStringLength()const
 {
     return _labelRenderer->getStringLength();
 }
diff --git a/cocos/ui/UIText.h b/cocos/ui/UIText.h
index 3b2690b3f0..408a93623a 100644
--- a/cocos/ui/UIText.h
+++ b/cocos/ui/UIText.h
@@ -87,7 +87,7 @@ public:
      *
      * @return  string length.
      */
-    ssize_t getStringLength();
+    ssize_t getStringLength()const;
 
     /**
      * Sets the font size of label.
diff --git a/cocos/ui/UITextAtlas.cpp b/cocos/ui/UITextAtlas.cpp
index bce366478b..d249f4422b 100644
--- a/cocos/ui/UITextAtlas.cpp
+++ b/cocos/ui/UITextAtlas.cpp
@@ -114,7 +114,7 @@ const std::string& TextAtlas::getString() const
     return _labelAtlasRenderer->getString();
 }
     
-ssize_t TextAtlas::getStringLength()
+ssize_t TextAtlas::getStringLength()const
 {
     return _labelAtlasRenderer->getStringLength();
 }
diff --git a/cocos/ui/UITextAtlas.h b/cocos/ui/UITextAtlas.h
index 18942830bd..4ffa93f927 100644
--- a/cocos/ui/UITextAtlas.h
+++ b/cocos/ui/UITextAtlas.h
@@ -87,7 +87,7 @@ public:
      *
      * @return  string length.
      */
-    ssize_t getStringLength();
+    ssize_t getStringLength()const;
     
     //override "getVirtualRendererSize" method of widget.
     virtual const Size& getVirtualRendererSize() const override;
diff --git a/cocos/ui/UITextBMFont.cpp b/cocos/ui/UITextBMFont.cpp
index 28b6e050a5..f6769ee2dc 100644
--- a/cocos/ui/UITextBMFont.cpp
+++ b/cocos/ui/UITextBMFont.cpp
@@ -108,7 +108,7 @@ const std::string& TextBMFont::getString()const
     return _stringValue;
 }
     
-ssize_t TextBMFont::getStringLength()
+ssize_t TextBMFont::getStringLength()const
 {
     return _labelBMFontRenderer->getStringLength();
 }
diff --git a/cocos/ui/UITextBMFont.h b/cocos/ui/UITextBMFont.h
index 03c3334555..5cca667916 100644
--- a/cocos/ui/UITextBMFont.h
+++ b/cocos/ui/UITextBMFont.h
@@ -76,7 +76,7 @@ public:
      *
      * @return  string length.
      */
-    ssize_t getStringLength();
+    ssize_t getStringLength()const;
 
     virtual const Size& getVirtualRendererSize() const override;
     virtual Node* getVirtualRenderer() override;