Abstract: Recently, the S&T evaluation has become one of the key issues in China's S&T development. In this paper, the problems are revisited from the perspective of S&T management. Through the characteristic and management process of knowledge production, this paper shows that scientific institution is similar to craft administration system and it is managed by reputation since R&D activity has high uncertainty. Consequently, it is found that the root of the China's S&T Evaluation lies in the invalidation of scientific community's internal management, as well as the weakness of the scientist markets.