In this paper, we propose a new design of circulation system of digital music contents in P2P service. It has functions of contents recognition, management of copyright DB, clearing house to perform payment system of P2P service. In P2P service each user provides his music contents, but in other circulation system, service providers provide their music contents. Therefore it is very difficult for each provider to recognize whatever the quality of distributing contents are good or not. Most circulation systems use hash technology or contents recognition technology for the recognition of contents. For the usability and efficiency this proposed system provides the combining technology of hash processing and contents recognition.