Abstract: The P2P network has been used more and more widely for its conveniency and flexibility，while the security risk of business activity is latent in the same time.To solve this problem of E-commerce system，this paper proposes a new trust model APR which is based on anticipative perceived risk.The concept of perceived risk is introduced into APR，many kinds of trust factor are taken to calculate the trust value among nodes，and an origination method is provided to integrate direct trust and recommendation trust.Comparing with other trust models，APR guarantees the valuation accuracy of trust model and sharpens the anti-risk ability of nodes.

Key words: Peer-to-Peer（P2P） system, E-commerce, trust model, perceived risk

摘要： P2P环境下的电子商务比传统电子商务更方便、更灵活，但用户也面临着更大的安全威胁和风险。为了解决P2P电子商务中的安全问题，提出了一种基于感知风险度的P2P电子商务信任模型APR。引入感知风险度的概念，综合多维的风险因素用以辅助计算网络中节点实体的信任度，并给出了完整的综合直接信任与推荐信任的方法。仿真实验证明，与其他的信任模型相比，APR可以保证信任评估的准确率，提高节点的抗风险能力。

关键词: P2P, 电子商务, 信任模型, 感知风险