Based on Geographic Information System(GIS)

at a 1 km×1 km grid size

by choosing terrain

land cover

climate and water resources as evaluation factors

this paper establishes the human settlement environment model

calculates the human settlement environment index(HEI) of Guangdong

analyses the regional differences of natural suitability of human settlement environment and discusses the suitable and restrictive factors of different regions in Guangdong Province. The results show that: the HEI of Guangdong ranges from 29.6 to 91.2; the natural environment suitability decreases both from the central region to the south and from the central region to the north of Guangdong. Considering area and population

the comparatively suitable region ranks first in both aspects

accounting for 67.46% of the total area and 71.07% of the total population of Guangdong; the common suitable region accounts for 288% of the total area and 21.54% of the total population of Guangdong; the most desirable region -accounts for 2.97% of the total area and 7.32% of the total population of Guangdong; the low suitable region has the lowest percentage in both aspects

with 0.77% of the total area and 0.07% of the population of Guangdong. Salient relief is a common bottleneck of natural suitability for human settlement in northern Guangdong

while surface water shortage and hot climate are the main disadvantages of natural environment suitability in Zhanjiang and Maoming. Sparse vegetation is the main natural restriction to natural suitability of some developed regions in the Pearl River Delta

while most common suitable regions are restricted by two or more natural factors.