The P4P architecture is mainly composed of appTracker, iTracker and peer. The single appTracker manages sharing resources in the different ISP domains. Every peer registers with appTracker when joining the network, and then requests resources from appTracker. In this architecture, there is too much workload for the single appTracker, thus, the bottleneck problem often appears when the scale of the network is enlarged in this centralised structure. An improved design of P4P based on distributed tracker is proposed to solve the overload problem of single appTracker server. In the improved P4P system, a distributed tracker overlay network replaces the appTracker to manage the resources in the different ISP domains. The functions of iTracker arranged by ISP are extended and the info interfaces of the iTracker are designed in detail in order to realise sharing the resources among the different iTrackers. The experiments prove that the P4P framework based on the distributed tracker can solve the server bottleneck problem and improve the scalability and stability while maintaining the characteristics of locality and transmission capacity.