Considering autonomy character of distributed nodes, we propose a distributed storage model for selfish and rational nodes (SR-DSM). SR-DSM is designed as six-layer model. First, static conception is described in formalization method, in which conceptions of Physical Entity (PE), Storage Service Entity (SSE) and User Entity (UE) are proposed. Second, main realization issues promoting cooperation are discussed, which is the P2P overlay network, providing of incentive compatible storage resource and selection using mechanism design, and replica placement using game theory. At last, for SSE is considered as chief active subject in model, dynamic behavior of SSE is abstracted by Petri network which is used to analyze user initial demand satisfaction with the P2P measured data. SR-DSM not only satisfies the character of selfishness and rationality, but also strengthens cooperation among nodes. And advantages of scalability, decentralized controls are still kept.