diff --git a/cocos/renderer/CCTexture2D.cpp b/cocos/renderer/CCTexture2D.cpp
index 49273110e6..57f447c610 100644
--- a/cocos/renderer/CCTexture2D.cpp
+++ b/cocos/renderer/CCTexture2D.cpp
@@ -322,6 +322,15 @@ void Texture2D::convertRGBA8888ToRGB565(const unsigned char* data, ssize_t dataL
     }
 }
 
+// RRRRRRRRGGGGGGGGBBBBBBBB -> AAAAAAAA
+void Texture2D::convertRGB888ToA8(const unsigned char* data, ssize_t dataLen, unsigned char* outData)
+{
+    for (ssize_t i = 0, l = dataLen - 2; i < l; i += 3)
+    {
+        *outData++ = (data[i] * 299 + data[i + 1] * 587 + data[i + 2] * 114 + 500) / 1000;  //A =  (R*299 + G*587 + B*114 + 500) / 1000
+    }
+}
+
 // RRRRRRRRGGGGGGGGBBBBBBBB -> IIIIIIII
 void Texture2D::convertRGB888ToI8(const unsigned char* data, ssize_t dataLen, unsigned char* outData)
 {
@@ -917,6 +926,11 @@ Texture2D::PixelFormat Texture2D::convertRGB888ToFormat(const unsigned char* dat
         *outData = (unsigned char*)malloc(sizeof(unsigned char) * (*outDataLen));
         convertRGB888ToRGB565(data, dataLen, *outData);
         break;
+    case PixelFormat::A8:
+        *outDataLen = dataLen/3;
+        *outData = (unsigned char*)malloc(sizeof(unsigned char) * (*outDataLen));
+        convertRGB888ToA8(data, dataLen, *outData);
+        break;
     case PixelFormat::I8:
         *outDataLen = dataLen/3;
         *outData = (unsigned char*)malloc(sizeof(unsigned char) * (*outDataLen));
diff --git a/cocos/renderer/CCTexture2D.h b/cocos/renderer/CCTexture2D.h
index c88dbe7fe7..6a04e69b99 100644
--- a/cocos/renderer/CCTexture2D.h
+++ b/cocos/renderer/CCTexture2D.h
@@ -489,6 +489,7 @@ private:
     //RGB888 to XXX
     static void convertRGB888ToRGBA8888(const unsigned char* data, ssize_t dataLen, unsigned char* outData);
     static void convertRGB888ToRGB565(const unsigned char* data, ssize_t dataLen, unsigned char* outData);
+    static void convertRGB888ToA8(const unsigned char* data, ssize_t dataLen, unsigned char* outData);
     static void convertRGB888ToI8(const unsigned char* data, ssize_t dataLen, unsigned char* outData);
     static void convertRGB888ToAI88(const unsigned char* data, ssize_t dataLen, unsigned char* outData);
     static void convertRGB888ToRGBA4444(const unsigned char* data, ssize_t dataLen, unsigned char* outData);