Abstract-Semantic overlay could improve query performance in peer-to-peer (P2P) systems. When peers join or leave frequently, it will lead to network traffic surge, since most semantic search methods maintaining a large number of routing tables. In this paper, we address these problems by proposing Interest Attenuation Search(INS), a novel efficient peer-to-peer semantic search approach based on interest attenuation policy. In INS, the interest attenuation policy is introduced to help peers decide whether to forward messages. Before peer floods the request in semantic overlay network(SON), it will check the history information about the request message, then uses INS to make forwarding decision. Simulation results show that INS significantly improves query performance and reduces the traffic overhead generated by unstable network environment.