diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a60453ff4e3bba6e6cb3b3de915dd69afd3a1ec3..bf4ac0112035d42d55944b1ceab80dac95367fbc 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -1,5 +1,7 @@
 # Contribute Code
 
+To get started, <a href="https://www.clahub.com/agreements/wangkuiyi/Paddle">sign the Contributor License Agreement</a>.
+
 We sincerely appreciate your contribution.  This document explains our workflow and work style.
 
 ## Workflow