diff --git a/paddle/fluid/operators/mkldnn/conv_mkldnn_op.cc b/paddle/fluid/operators/mkldnn/conv_mkldnn_op.cc
index b333b42c0142dbe8ea2e28dfde754b64e1d71089..5bba3c6d6ed6b279c8e9c1925dea124bb213e09b 100644
--- a/paddle/fluid/operators/mkldnn/conv_mkldnn_op.cc
+++ b/paddle/fluid/operators/mkldnn/conv_mkldnn_op.cc
@@ -191,7 +191,6 @@ class ConvMKLDNNHandlerT
 
       UpdatePaddingAndDilation(&paddings, &dilations, padding_algorithm,
                                data_dims, strides, ksize);
-      const bool is_conv3d = strides.size() == 3U;
 
       std::transform(dilations.begin(), dilations.end(), dilations.begin(),
                      [](int64_t i) { return i - 1; });