With the chance of entering WTO, China is promoting the rebuilding of conformity assessment system in order to conform to WTO/TBT requirement and international conformity assessment system. Firstly, this research make it clear that the importance of conformity assessment activity, and the international movement of conformity assessment activity. Secondly, this paper surveyed the development course of conformity assessment activity and it's present operating system in China. Finally, this paper concludes the problems of present conformity assessment activity and implies the improving scheme. In the meantime, it also point out the later possible research topic in this field.