diff --git a/doc/build/build_from_source.md b/doc/build/build_from_source.md
index 2c32c37e9ddf58432abec31ed7954c3ebc1e9716..36681727f6430e09c6a10ac7189ada049d627687 100644
--- a/doc/build/build_from_source.md
+++ b/doc/build/build_from_source.md
@@ -125,6 +125,8 @@ mkdir build
 cd build
 # you can add build option here, such as:    
 cmake -DWITH_GPU=ON -DWITH_DOC=OFF -DCMAKE_INSTALL_PREFIX=<path to install> ..
+# please use sudo make install, if you want
+# to install PaddlePaddle into the system
 make -j `nproc` && make install
 # PaddlePaddle installation path
 export PATH=<path to install>/bin:$PATH