diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8f7a0c5..962083a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@
   - Fix unexpected 'No active span' IllegalStateError (#311)
   - **Tentative**: Set upper bound <=5.9.5 for psutil package due to test failure. (#326)
   - Remove `DeprecationWarning` from `pkg_resources` by replace it with `importlib_metadata` (#329)
+  - Fix unexpected 'decode' AttributeError when MySQLdb module is mapped by PyMySQL (#336)
 
 ### 1.0.1
 
diff --git a/skywalking/plugins/sw_mysqlclient.py b/skywalking/plugins/sw_mysqlclient.py
index 9adbc5b..bf86ba8 100644
--- a/skywalking/plugins/sw_mysqlclient.py
+++ b/skywalking/plugins/sw_mysqlclient.py
@@ -32,6 +32,9 @@
     import wrapt
     import MySQLdb
 
+    if hasattr(MySQLdb, 'install_as_MySQLdb'):
+        raise ImportError('SKIP MySQLdb module mapped by PyMySQL', name='MySQLdb', path='')
+
     _connect = MySQLdb.connect
 
     def _sw_connect(*args, **kwargs):