In 2008, the concept of shadow banking was proposed at first time. Many people considered that the US financial crisis was because the shadow banking. FSB investigated 26 major countries in 2011, and discovered that the scale of shadow banking worth more than $ 67 trillion. China accounts for 4-5%, about 20 to 30 trillion Chinese Yuan. Recently, scholars have gradually indicated that China must face the importance and influence of shadow banking. This paper will discuss the development factors of shadow banking through the analysis of PEST and its influences from the government, commercial banks and enterprises.