diff --git a/cocos2dx/textures/CCTextureCache.cpp b/cocos2dx/textures/CCTextureCache.cpp
index 4dbfc57cbd..46d6e12047 100644
--- a/cocos2dx/textures/CCTextureCache.cpp
+++ b/cocos2dx/textures/CCTextureCache.cpp
@@ -469,7 +469,6 @@ CCTexture2D * CCTextureCache::addPVRImage(const char* path)
 	return tex;
 }
 
-
 CCTexture2D* CCTextureCache::addUIImage(CCImage *image, const char *key)
 {
 	CCAssert(image != NULL, "TextureCache: image MUST not be nill");
@@ -482,6 +481,9 @@ CCTexture2D* CCTextureCache::addUIImage(CCImage *image, const char *key)
 		forKey = CCFileUtils::fullPathFromRelativePath(key);
 	}
 
+	// Don't have to lock here, because addImageAsync() will not 
+	// invoke opengl function in loading thread.
+
 	do 
 	{
 		// If key is nil, then create a new texture each time