Abstract: S&T service system is very important to support "Three Rural Issues "(agriculture, rural areas and farmers). It is the result of market economic development and an important way to develop China's modern agriculture. In this article, we think there are several following things we should do to develop rural S&T service system. First,we should afford full comprehensive service to develop rural market economic development. Second, we should build a diversify S&T service provider . Third, we should perfect rural S&T service system mechanism, and so on. This article also gives some other suggestions to develop S&T service system.