Abstract: Abstract: With the rapid economic and social development, more and more concerns are on the survival of their own settlement environment. Human settlement environment is not only the basic space of human existence and activities, but also the concentrated expression of human civilization. In this paper, the Human Settlements Environment Index (HEI) model was built to evaluate the environmental suitability for human settlements in Kai-Kong River Basin, using the selected relief degree index, vegetation index, humidity index, hydrology index, and land use evaluation index, with the grid scale of 1 km×1 km. Through applying spatial analysis technique of ArcGIS software including spatial overlay analysis and density analysis，the spatial situation of human settlement environment suitability and spatial pattern for human living environment in Kai-Kong River Basin were systematically summarized and established .The results showed that the index of nature suitability for human settlement in the Kai-Kong River Basin was between 4.4 and 83.9. According to the correlation between the human distribution and the human environment index the human settlement environment in Kai-Kong river divided into five region, they are high suitable region, suitable region, general suitable region, unsuitable region and least suitable region. In general, suitability for human living environment decreased from middle plain areas to Tianshan mountain areas in the northwest and Taklimakan desert areas in the southeast．In the study area，the high suitable region was mainly distributed in Korla city, which accounted for about 124 km2, 0.2% of the total area of the study region. Suitable region was mainly distributed in bordering area of Bohu, Hejing, Heshuo, Yanji and Yuli county, which accounted for about 2456 km2, 3.3% of the total area of the study region. General suitable region was mainly distributed in around the suitable region, which accounted for about 2 526 km2, 3.4% of the total area, this area was mainly located in the intersecting zone, so that it has a great potential for development. The unsuitable region was mainly distributed in upper stream of Kai-Kong River Basin which covered by snow and accounted for about 23 104 km2, 31% of the total area. The least suitable region was mainly distributed southwest part of the study area, this area was mainly composed by desert that characterized with high temperature, high evaporation, low precipitation and low vegetation cover, not suitable for human living and development, and it constitutes the largest parts of the whole study area, which accounted for about 46 301 km2, 62.1% of the total area. High Suitable regions and suitable regions for human living were distributed mainly around Kai-Kong River connecting region in the form of ribbons and batches. The high suitable region, suitable region and general suitable region accounted for 6.9% the total area of study region, and 98.8% of the total population in this area. Unsuitable region and the least suitable region accounts for 93.1% of the total study area, and only 1.2% of the total population distribution in this region. Results also indicated that the geographical environment of the study area is rather fragile. Therefore, it is not suitable for increasing population and conducting irrational land development activities in the Kai-Kong Rivers Basin. Spatial distribution of population was influenced and controlled by severe environmental conditions, such as the constantly expanding of deserts, the high terrains, and the complicated climate as well as the lack of hydrological conditions. Irrational agricultural production activities and slow economic growth was also the huge obstacles of suitability for human living environment in the Kai-Kong River Basin. According to these problems and various planning，it can be suggested that some of the residential areas are needed to relocate, in order to improve situation of residential environment.