Abstract:To understand the role of urban forests in the heat island, the heat island effect and its relationships with the pattern of urban forests in Chendu, Sichuan Province, has been analysed in this paper. The pattern of urban forests in Chendu was derived from spot and landsat-7 images using GIS. The dynamic model was established based on land use/cover types, meteological data and statistic data of green cover, which has been used for the comprehensive analysis on the relationships between heat island effect and urban forest pattern. The result shows that the heat distribute more in the northwest of Chengdu than in the southeast, which is on the contrary of the urban forest pattern. The higher the urban green coverage, the more apparent the cooling effect. Under a certain green coverage, a large area of greenbelt has a higher heat reduction than the smaller one. This suggests that at the same time of reasonable planning of the urban forest pattern, it is necessary to appropriatly increase the size of urban forest park.