Abstract: The landsat images of 1989, 2003 and 2018 are used to invert the surface temperature of Xixiu District of Anshun City. Then, the study area's spatio-temporal variations and their causes of heat island development in the past 30 years are analyzed. In addition, the image-based inversion algorithm and the classification regression tree algorithm are combined to invert the surface temperature. After that, the accuracy of the inversion results are made through the weather station data. And a buffer is established for quantitative analysis such as correlation analysis in the study area. From the above researches, the results show that:First, the study area is affected by karst landforms, besides the main urban area, there are also a large number of high temperature areas in the suburbs. Second, in the past 30 years, the thermal effect of the study area has a significant correlation with the impervious surface and the area of green space. Finally, from 1989 to 2003, the urban heat island area of the study area gradually increased with urban expansion, but in 2018, the urban heat island phenomenon in the main urban area almost disappeared. After excluding the influence of meteorological factors and urban morphological factors, it is found that this is closely related to the vigorous urban greening in Anshun.

Key words: urban heat island, land cover, impermeable water surface, karst, afforestation of city