diff --git a/README.md b/README.md
index 883e965..3bf198f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # tianshou
 Tianshou(天授) is a reinforcement learning platform.
+
+![alt text](https://github.com/sproblvem/tianshou/blob/master/docs/figures/tianshou_architecture.png "Architecture of tianshou")
+
 ## data
 TODO:
 
@@ -25,3 +28,34 @@ MCTS
 ## agent (optional)
 
 DQNAgent etc.
+
+## Pontential Bugs:
+
+0. Wrong calculation of eval value
+
+UCTNode.cpp
+```
+106     if (to_move == FastBoard::WHITE) {
+107         net_eval = 1.0f - net_eval;
+108     }
+
+309         if (tomove == FastBoard::WHITE) {
+310             score = 1.0f - score;
+311         }
+```
+
+1. create children only on leaf node
+
+UCTSearch.cpp
+```
+ 60     if (!node->has_children() && m_nodes < MAX_TREE_SIZE) {
+ 61         float eval;
+ 62         auto success = node->create_children(m_nodes, currstate, eval);
+ 63         if (success) {
+ 64             result = SearchResult(eval);
+ 65         }
+ 66     }
+```
+
+
+