Nowadays global competition has become more and more rigorous when entrepreneur operates a company in e-commerce industry. Companies, which don’t acknowledge the effective ways to respond to global competition, fail to gain more market share and there is also a risk of losing their occupied market share. It is important for companies to respond to competition effectively. By using Porter’s five forces model, we can analyze how companies respond to competition more comprehensive.     The purpose of this thesis is to demonstrate some of competition that companies face and analyze how companies respond to competition when operating in e-commerce industry.   In this thesis, we use a case study to analyze two companies’ competition strategies so as to develop an understanding of the e-commerce competitive environment and realize the importance of responding to various competitions in e-commerce market. In order to gather the important information, we interview respondents of two Chinese B2C companies. Two B2C companies are: JD Company and Amazon China. JD Company is a domestic company and Amazon China is a multinational company.   This study demonstrates that the companies need to improve their competitiveness to respond to competition such as improving the quality of product, the logistic system, and the after-sale service. In addition, it is better for companies to make the strategies such as low-price strategy and differentiation strategy to respond to competition.