The issue of firm growth has long been regarded as an essential concern in the economics and management field. In recent years, the information and Internet technology has been improving in an increasing speed. Internet firms have occupied a vigorous position in the economy. How Internet firms keep develop in the fierce competition and what the key factors are in the growth of Internet firms are becoming a hot topic in the field of company management. This paper tries to study the key factors in the growth of Internet firms based on data of listed Chinese Internet companies by adopting empirical method and using factor analysis method and multiple linear regressions.