Concession pricing is the key to success of PPP project. There are many stakeholders in PPP project of rural sewage treatment and it is necessary to comprehensively consider social welfare, government financial pressure and reasonable interests of enterprise. The factors affecting concession pricing of PPP project are complicated and interrelated. This study analyzes the concession pricing target of different stakeholders in PPP projects of rural sewage treatment and identifies the critical factors. The relationship of these factors is clarified based on ISM. The results show that project expected rate of return is the direct influence factor and per capita disposable income is the root of the factor that affects concession pricing. The study results will provide governments with management implications to prepare equitable concession price.