Abstract: Taking the Western New City of Chongqing as the research area, we compared Markov model and CA-Markov model in simulating the urban expansion so as to verify the advancement of CA-Markov model. Then we used CA-Markov model to predict the urban expansion pattern of the Western New City in 2030, and analyzed the spatial-temporal evolution characteristics and ecological response of urban expansion from 2007 to 2030. The research results show that:1) Compared with Markov model, CA-Markov model has a better area simulation capability and makes up for the former's lack of spatial pattern simulation capability, whose Kappa coefficient is up to 82.97%. 2) The area, rate, and intensity of urban expansion in Western New City of Chongqing from 2007 to 2018 were 1 568.78 hm², 5.74%, and 1.20%, respectively, while the counterparts predicted from 2018 to 2030 will be 71.62 hm², 0.15%, and 0.05%, respectively. It shows that the urban development period of Western New City of Chongqing will change from the rapid urbanization stage to the saturation stage of urban expansion. 3) There are significant spatial differences in urban expansion of the study area. The construction land has gradually expanded from the western agglomeration to the "n"-shaped area composed of the west, north, and east in the study area, and it has changed from extensional expansion to internal expansion. 4) The ecological protection and urban expansion in the study area have undergone the evolution process of "joint advancement-confrontation-stability", and the scope of ecological land in some areas will expand in the future. To a certain extent, it has avoided the blind urban expansion, and the development of urban construction and the ecological protection will achieve a better balance. Political factor may play a significantly leading role in the ecological response of Western New City of Chongqing.

Key words: urban expansion, CA-Markov model, spatial-temporal evolution simulation, ecological response, Western New City of Chongqing