diff --git a/paddle/fluid/operators/reduce_ops/reduce_sum_op.cc b/paddle/fluid/operators/reduce_ops/reduce_sum_op.cc
index 32b9a0639ad2d1929e1f13a86f2c6a82da914c92..8844c5a89732992314948df446ec13d95930f39b 100644
--- a/paddle/fluid/operators/reduce_ops/reduce_sum_op.cc
+++ b/paddle/fluid/operators/reduce_ops/reduce_sum_op.cc
@@ -121,7 +121,7 @@ REGISTER_OPERATOR(reduce_sum, ops::ReduceOp, ReduceSumOpMaker,
                   ops::ReduceSumOpGradMaker<paddle::framework::OpDesc>,
                   ops::ReduceSumOpGradMaker<paddle::imperative::OpBase>);
 REGISTER_OPERATOR(reduce_sum_grad, ops::ReduceGradOp,
-                  i ops::ReduceSumDoubleGradDescMaker,
+                  ops::ReduceSumDoubleGradDescMaker,
                   ops::ReduceSumDoubleGradOpBaseMaker,
                   ops::ReduceSumGradNoNeedBufferVarInferer);