Understanding the spatial characteristics of land suitable for settlement construction underlies urban master planning and subject planning and helps to alleviate the pressure of population growth and economic development in areas of limited land resources. The research community, however, has mainly focused on rapid urbanization areas such as regional metropolitan areas. This study used the multi-factors overlay comprehensive evaluation method to evaluate the spatial characteristics of land suitable for settlement construction. Specifically, we chose the Qinling mountains as a typical example, which are of vital importance in determining suitable land in mountainous areas where the carrying capacity of the environment is sensitive and weak. Using a geographic information system (GIS) and remote sensing technology, we revealed the spatial characteristics of settlement construction suitability, which utilized 14 indicators taken from natural geography, ecology and socio-economic data. We ascertained the weight of each indicator using an analytic hierarchy process method, and thereby determined the amount of land suitable for settlement construction in various counties. The main results were as follows: (1) Areas with different levels of suitability appeared to have significant differences. Most of the Qinling mountains are not suitable for settlement construction. The area of optimum land available for settlement construction in this region was 3378.1 km², accounting for 5.87% of the study area-a relatively small proportion of suitable land. (2) Land suitable for settlement construction in the Qinling mountains showed an obviously spatial heterogeneity: The most appropriate land was concentrated in North and South Piedmont and East Valley, which showed obvious mountainous features. (3) Results of gap analysis in the built-up area showed that 9.15% of built-up settlements were distributed in restricted construction regions, especially in counties such as Foping, Zhouzhi, Huxian, Taibai as well as Yangxian, which presented ecological safety risks. (4) There were 3192.27 km² of land suitable for settlement construction, distributed unequally in spatial terms. Most of these areas were distributed in counties such as Shangluo, Hangyin, Shanyang and Lueyang, and some other counties. In Foping, there was only 2 km² available for settlement construction. (5) In order to more effectively apply the results to urban system planning and biodiversity conservation in the Qinling mountains, we proposed the following recommendation: Consider both the actual location of the various towns and the results of the suitability evaluation for settlement construction when determining the future pattern of urban development. This study provides an insight into a suitability evaluation for settlement construction in a mountainous area. These findings provide scientific support for urban planning and for estimating the area of suitable land, while the research methods and reasoning used can help to achieve a win-win scenario between urbanization and biodiversity conservation.