The motion of urbanization development can be classified into benefit motion, industrial development motion and other motions, all kinds of motions for boosting urbanization development in this area need to be analyzed in order to take relevant measures to improve urbanization level of Chongqing. Grey association method is used to analyze the role of all urbanization motions in the process of urbanization development since Chongqing became the municipality directly under central government, and the results show that economic benefit disparity between urban and rural areas is the main motion for urbanization, that the driving force from outside Chongqing is stronger than that of industrial development from inside, that rural driving force is obvious and that non-economic benefit motion, especially the motion of educational environment, also plays a certain role. Chongqing should build long-term mechanism for the growth of residents’ income in the whole Chongqing, actively help Chongqing’s rural surplus labors to be employed in Chongqing instead of going to outside, accelerate rural development and enhance supply ability of urban public facilities and public service.