According to the dialectical relation of interest and power, the local government has an inner requirement for seeking and strengthening its interest and power, which exactly produces the fundamental impetus for the change in the administrative power of the local government. This fundamental impetus consists of the orientation of the change in the Central Government, the trend of the enlargement in the local government and the liberalization of regional markets. And the interaction among the three factors forms its inner mechanism. Under the affection of the mechanism, there appear different types of changes for the administrative power in the local government. But, due to the existing structure of the political system, and with the development of the local economy, all types of local governments can enlarge their administrative powers. It is a general tendency.