Introducing micro-payment mechanism into P2P systems will bring economic incentives to various P2P applications and encourage peers to share their resources. In this paper, we present a new micropayment protocol, CPay, which exploits unique characteristics of P2P systems. The protocol establishes dynamic consistent hashing map between the set of all peers in the system and its subset of high performance peers. In each transaction, the payer?s corresponding high performance peer checks the transaction to make sure that any illegal use of the ecoin will be timely detected. The protocol effectively exploits the heterogeneity of the P2P system and can achieve load balance.