diff --git a/include/cos_defines.h b/include/cos_defines.h
index a485b7d..00c32c6 100644
--- a/include/cos_defines.h
+++ b/include/cos_defines.h
@@ -11,7 +11,7 @@
 
 namespace qcloud_cos {
 
-#define COS_CPP_SDK_VERSON "v5.5.4"
+#define COS_CPP_SDK_VERSON "v5.5.6"
 
 /// 路径分隔符
 const std::string kPathDelimiter = "/";