We develop a simplified model in this paper for the deduction of self-organized evolution of P2P network. Our model reflects the interest pursuing in real world, so we emphasize nodes? trade-off between the value of information and the cost of establishing link. We transfer the self-organized evolution of network to a convergent stochastic process for the mathematic deduction and also provide a detailed deduction of network evolution. We point that PGP certificate network is a good instance of this model. Selforganization can be regarded as an invisible hand to dominate the development of network, and our work partly reveals this hand?s true features