As a new fashioned shopping mode, network shopping has been presenting a growth trend both in its user scale and transaction scale in recent years. Meanwhile, the complaints of network shopping are increasing by years which reveal many credit risks, such as fictitious trading, quality problem, price fraud, internet fraud and so on, that influenced greatly on the reputation formation of e-commerce enterprises. The reputation of e-commerce enterprise is regarded as the intangible assets of sustainable development which forms the competitive advantages of the enterprise. Based on the reputation thoery, this paper analyzes the condition of credit imperfection of online shopping by combining with the theory of the e-commerce chain in order to establish the optimized system of the reputation mechanism and promote healthy development of the e-commerce enterprises. Through the actual case study on e-commerce enterprises such as Alibaba, Jingdong, this study estabilshes the credit evaluation system of network shopping so as to improve the security of network shopping and increase the users' trust to e-commerce enterprises.