Abstract: Abstract: The city-level main functional division will be beneficial to flexibility of system design and maneuverability of space control policy. It will enhance the formation of the main economy and sustainable development. An ecological footprint model is a method adopted to evaluate human influence on resources and the environment and the extent of sustainable development. The article, adopting an improved ecological footprint as the technique for a city-level main functional division, establishes the main functional index system, and is interconnected with a spatial analysis of GIS. It adopts the county as the evaluation unit, and analyzes construction land suitability, natural reserves, and important ecological areas, modifying the spatial layout of the main function. The results demonstrate that: 1) Ecological pressure in the municipal area, except in Changqing County, is larger than that of the other urban area; on the contrary, the development potentiality in the former was smaller than that of the latter, which reflects an evident spatial pattern. 2) The limitation of each assessment unit was obvious, which is egarded as a basis of the main functional division, excluding the forbidden development area. 3) Through an overlay analysis of the original main functional division map with a construction land suitability evaluation map, a natural reserve map, and an important ecological area map, the original district division was modified. Shanghe County was changed from a key zone to a limited zone. The method of GIS combined with an ecological footprint model has been well applied in the main functional division.