Abstract: Abstract：The disorderly expansion of urban land leads to the decline of ecosystem service function, which affects the coordinated development of society, economy and ecology. Based on DMSP/OLS data, Landsat TM/OLS data, this paper analyzed the spatio-temporal characteristics of urban expansion. Meanwhile, based on MODIS NDVI data, crop yield data, land use data, meteorological data and soil type data, the spatial distribution and changes of food supply, NPP and runoff depth in 2005 and 2015 were simulated using food supply, model CASA model and SCS_CN model. Finally, through correlation analysis and normalization analysis, the changes of ecosystem services and trade-off or synergy are explained in different urbanization categories, discussed the problems and challenges in process of urban expansion, and gives some ideas for future urban development. The basic conclusions are as follows: ①The Chongqing city was separated into three urbanization categories (developing urban, developed urban, and rural areas). In terms of time, urban land has expanded dramatically, from 2005 to 2015 increased by 373.9 km, the urban land expansion was the smallest because of urban land distribution in developed areas was relatively saturated, development urban was the largest. In terms of space, urban land extends along the northeast and southwest directions, Yubei District and jiangbei District in the east-northeast direction were affected by the “liangjiang new area”, and the increment of urban land was the largest; ②In 2005 and 2015, the service functions of food supply, carbon sequestration and soil water storage were the lowest in developed urban areas, followed by development urban areas, and the highest in rural areas. In addition, the ecosystem service functions have showed tendency of significant decline, the largest decline area was development urban, which coincided spatially with the area with the greatest urban expansion, it showed that the change of land use type caused by urban expansion was an important reason for the decline of ecosystem service function; ③The trade-off and synergy between ecosystem services were affected by the degree of urban development; ④ Urban expansion has significant impacts on ecosystem services, the areas with biggest decline of ecosystem service was developing urban, and food supply was the most obvious service function of the recession. It was found that the rapid expansion of urban land destroys the ecosystem services, reduces the environmental capacity and affects the comfort of residence of citizens. In view of this, some ideas for the development of urban expansion are given at the end of this paper. The research results of this paper provide a scientific basis for analyzing the causes of the problems in the urbanization process, seeking the coordinated development, and Rational planning and development in Chongqing City.