Abstract: Based on a simplified evolutionary game model，this paper analyzes the internal mechanism of credit cheating behaviors in E-Commerce business.With regard to potentially technological or rule defaults in credit system as well as traders’ selfish rationality，presence of credit cheating is to some extent unavoidable.It then suggests a new kind of credit system，which is independently coexistent with traders and trading，should be set up to control credit cheating.Simulation experiments support the ideas aforementioned.