Abstract: Mobile P2P network is topology dynamic, mobile nodes resource limited, and network resource short. Considering the limitation of network resources and shortage of peer resources, how to make full use of mobile nodes' cooperative cache resources effectively and increase mobile nodes' cooperation is a challenging task to reduce network delay, save bandwidth and prevent congestion in mobile P2P networks. To solve this problem, the limited cooperative cache replacement policy establishment, the sufficient cooperative cache resource use and the key data buffering are discussed in detail in this paper. Moreover, according to the idea of ant colony algorithm, a cooperative cache replacement policy based on the pheromone is proposed, and a mathematical model and the derivation of choosing appropriate memory space as cooperative cache are established. The theory analysis and experiment results of this paper show that the new policy can significantly improve cooperative cache resource utility and improve network performance efficiently. It also can promote the mobile nodes' cooperation and success ratio of resource obtainment from neighbor nodes and reduce the average response delay of cooperative cache resource request.