diff --git a/python/paddle/fluid/metrics.py b/python/paddle/fluid/metrics.py
index a4503e75671d7d12ff84bb538776f8e6c832b9d1..f65b37903a35fa2bf9f2c2b2f169ce6fd4c478db 100644
--- a/python/paddle/fluid/metrics.py
+++ b/python/paddle/fluid/metrics.py
@@ -194,7 +194,7 @@ class CompositeMetric(MetricBase):
                                or soft-label, should custom the corresponding update rule.
         """
         for m in self._metrics:
-            ans.append(m.update(preds, labels))
+            m.update(preds, labels)
 
     def eval(self):
         """