Trust relationship between peers must to be established in P2P systems. But current trust models have some flaw in computing peer’s trust value, trust security and so on. This paper referred to the interpersonal social network, in which trust relationship between individuals are set up upon recommendations of other individuals, and proposed a recommendation trust model based on D-S evidence theory for P2P systems. The model deduces a peer’s local trust values from its transaction history, and then combines the peer’s local trust values by D-S combination rule and gets its global trust value finally. The experiment shows that, compared to the current trust model, the proposed model is more robust in security and more accurate in computing peer’s global trust value.