Abstract: In this paper,the land surface temperature(LST) of Beijing area is retrieved from Landsat TM thermal band data utilizing a radiative transfer equation and the urban heat island effect of Beijing and its relationship with land cover and vegetation index are discussed.The result of the LST shows that the urban LST is evidently higher than the suburban one.Thought comparison of LST,the authors find the average urban LST is 4.5℃ and 10℃ higher than the suburban and outer suburban temperature,respectively,which demonstrates the urban heat island effect being prominent.Prominent negative correlation between LST and NDVI is found in the urban area,which suggests the low fractional vegetation cover in the urban area is the main cause of the urban heat island.