According to the characteristics of moun-tain cities, this article puts forward the emphases of space control in urban planning area. Based on the land evaluation of ecological sensitivity, construc-tion suitability and the elements of ban-construction and restrict-construction, it analyzes how to effec-tively organize the land of the urban planning area, and presents a kind of operable research method for urban space control in mountain city by the data analysis of space and visual function affording by ArcGIS9.3 software. Meanwhile, combined with the case of the Changshou master planning ,which the author participsated in, it specifically displays the applied processes and results of the method.