diff --git a/README.md b/README.md
index 5dee49a..a581ea7 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
 # couponrpc
 
-优惠券rpc数据结构及方法
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+优惠券rpc数据结构及方法
+
+## IsAvailable(dbname, user_id, product_id, user_coupon_id string, url ...string)
+
+查询是否已领券
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