With the rapid development of C2C e-commerce,it is urgent to solve the reputation manipulation problem which hinders the construction of C2C e-commerce credit system.The motivation,interest,mode of operation and operation procedure of reputation manipulation were analyzed.After inspecting the credibility-manipulation impact on C2C e-commerce industry,the institution structure was analyzed by Sun chart and the observation intensity condition for governing the bad behavior was achieved.The introduced anti-fraud model for seller's reputation of C2C can control the C2C reputation manipulation by enhancing the observation intensity,which provides a theoretical basis for governing the reputation manipulation.A unified credit assessment criteria,an independent third-party platform as well as its internal whistle-blower system were given as advises.