Abstract: With query tree tag anti-collision protocol，tags need not to have additional memory except the ID.Moreover，the only computation required for each tag is to match its ID against the binary string in the query.Except the basic query tree protocol，there are many improved protocols.All these protocols just utilize the information tags send back[1，2].This paper presents a novel anti-collision protocol which uses the database of tags to identify tags more quickly.Theoretical results and simulation demonstrate the efficiency of the protocol.