 This paper examines the effect of urban heat island in Hong Kong using satellite imagery. It uses two algorithms to retrieve the land surface temperature, LST, from Landsat TM and Astrodata. The spatial patterns of LST are then used to characterize the local effects of urban heat island. Additionally, the correlation between LST and the Normalized Difference Vegetation Index, NDVI, and Normalized Difference Buildup Index, NDVI, is analyzed to explore the impacts of green land and built-up land on urban heat island. The results suggest that the effect of urban heat island is primarily concentrated in three sub-urban areas, Kowloon Island, Northern Hong Kong Island, and Hong Kong International Airport. The correlation between LST and NDVI shows that green land can weaken the effect of urban heat island, while the correlation between LST and NDVI suggests that built-up land can strengthen it. Despite the use of satellite imagery, further research should be conducted to improve the accuracy of the methods used. This article was authored by Lin Lu and Yuan Zhijian. We are article.tv, links in the description below.