diff --git a/doc/design/distributed_lookup_table_design.md b/doc/fluid/design/dist_train/distributed_lookup_table_design.md
similarity index 97%
rename from doc/design/distributed_lookup_table_design.md
rename to doc/fluid/design/dist_train/distributed_lookup_table_design.md
index a09f2818c888397b07fc7d09ecd20056f4176982..e543adf0f97cc6b47415b807d7a1ed1effec9b22 100644
--- a/doc/design/distributed_lookup_table_design.md
+++ b/doc/fluid/design/dist_train/distributed_lookup_table_design.md
@@ -26,7 +26,7 @@ lookup of rows.
 The following figure illustrates the multiplication of x with two
 non-zero elements, or say, two symbols, and a lookup table W:
 
-![lookup table](./lookup_table.png)
+![lookup table](./src/lookup_table.png)
 
 ### The Backward Algorithm
 
@@ -42,7 +42,7 @@ or some more sophisticated algorithms that rely on both W' and W:
 $$W = f(W, W')$$
 
 The following figure illustrates the backward pass of the lookup
-operator: ![lookup table training](./lookup_table_training.png)
+operator: ![lookup table training](./src/lookup_table_training.png)
 
 ## Distributed Storage Service
 
diff --git a/doc/design/lookup_table.png b/doc/fluid/design/dist_train/src/lookup_table.png
similarity index 100%
rename from doc/design/lookup_table.png
rename to doc/fluid/design/dist_train/src/lookup_table.png
diff --git a/doc/design/lookup_table_training.png b/doc/fluid/design/dist_train/src/lookup_table_training.png
similarity index 100%
rename from doc/design/lookup_table_training.png
rename to doc/fluid/design/dist_train/src/lookup_table_training.png