Abstract: The scientific measurement of the suitability of the natural environment of human settlements will be conducive to guide reasonably the population distribution and mobility, and promote the coordinated development of regional population and the resources and environment. By using GIS technology and taking 250 m×250 m grid as the basic unit, the climate, topography, hydrology, ground cover, natural disasters and other factors were selected to construct the natural suitability evaluation model of human settlements and evaluate quantitatively the natural suitability of human settlements in Anhui Province. On this basis, suitability and restrictive factors of each type of area are analyzed. The research shows that the index of natural suitability of human settlements in Anhui Province is between 33.64 and 74.58, and the natural suitability of human settlements is generally good, and most of the areas are suitable for human settlements, and there is a general trend of “higher in the south while lower in the north” in space which is just opposite to the existing population distribution pattern. Considering area, the general suitable region is the most extensive, accounting for about 46.08% of the total area of Anhui Province; the more suitable region ranks second, about 31.29% of the total; the highly suitable region accounts for 22.54% of the total; the critically suitable region is the smallest, only about 0.08%. About 61.16% of Anhui’s population is concentrated in the general suitable region. The percentage of the highly suitable region and the more suitable region’s population is less than 40%. The critically suitable region’s population is extremely scarce. Topographic relief and hydrological index are the main factors that cause the natural suitability of the human settlements in the whole province, and the evaluation results reflect objectively the natural background of the human settlements in Anhui Province. The space for the provincial population survival and development is fairly large, and there is a wider suitable range for population mobility and agglomeration.
Key words：human settlements；natural suitability；grid；GIS；Anhui Province