diff --git a/paddle/fluid/inference/analysis/analyzer.h b/paddle/fluid/inference/analysis/analyzer.h
index b5dc1fbbe7d1c67a713294d7d6958647e58008ae..6edfc9dd117fbaa723b9af2162aea247b8aa97ea 100644
--- a/paddle/fluid/inference/analysis/analyzer.h
+++ b/paddle/fluid/inference/analysis/analyzer.h
@@ -68,6 +68,7 @@ class Analyzer : public OrderedRegistry<PassManager> {
   const std::vector<std::string> all_ir_passes_{{
 // Manual update the passes here.
 #ifdef PADDLE_WITH_MKLDNN
+      // This pass should run before any other convolution fuse.
       "depthwise_conv_mkldnn_pass",  //
 #endif
       "attention_lstm_fuse_pass",       //