Abstract: The essay is based on the analysis of policy-oriented financial institutions, state-owned commercial financial institutions, cooperative financial institutions and non-formal financial institutions. The major point is that the overall function of the rural financial system is weakened. It analyzes the superiorities and conditions of supply and marketing cooperatives in the innovation of rural financial service system from the aspects of the organization of supply and marketing cooperatives and farmers allies. It tries to seize the feature of rural credit and put credit cooperative into the business service system based on the production and business cooperation in order to construct a new system of rural financial services whose foundation is the mutual funds of members of cooperatives. What's more, the essay puts forward the suggestion that we should grasp the basic orientation, focus on institutional innovation and the partnership of agricultural banks, prevent possible risks and get support from the government. These suggestions will promote cooperative-financial construction and innovate rural financial service system.