The growing and formation of urban cluster should be conditioned by the economic, social, cultural, natural, and other various complicated factors under a certain law. The growing mechanism of urban cluster, named as the NDESR Mechanism Model in this paper, has been creatively built, based on the key research ideas and methodology from Fishbone-Cause and Effect Diagram and System Dynamics. The model consists of five main sets, including the congenital conditions (called as Natures), the drivers (called as Drivers), the mechanism functions (called as Effects), the present situation and tendency (called as States), and the responses from human (called as Responses), in which the merging effects of factor mobility, the coupling effects of industrial division, the flexibility effects of knowledge accumulation, and the symbiotic effects of city scale expansion are the key function mechanisms that drive the urban cluster to senior evolution.
