Abstract: The rational delimitation of urban development boundary plays an important role in guiding the orderly growth of urban space and ensure proper environment health of urban space. In this study, we evaluated the ecological sensitivity of Nanchang City from four aspects (soil erosion, habitat, geological disaster and water resource) and simulated urban expansion in 2020 based on CA-Markov and land use data in 2000, 2010 and 2015. Spatial decision-making analysis of the two aspects was carried out in combination to the future development of the study area. We proposed a new method of delimitating urban development boundary integrating environmental protection and urban development through the dynamic coordination of both aspects. The results showed that ecological sensitivity of Nanchang City was moderate. The scale of urban construction land based on CA Markov simulation was 1239.67 km², which slightly exceeded the planned construction land target (1201.65 km²). When the dynamic adjustment was done by superimposing the ecological sensitivity evaluation results with the expansion simulation results, the adjusted construction land scale of Nanchang City was 1193.15 km², which met the planned requirement. Consideration of the coordination of protection and development could not only protect the ecological space, but also help to guide the orderly growth of urban space and ensure the healthy development of urban space, and thus was an important way to achieve a win-win situation between rational urban development and ecological protection.