Land surface temperature(LST)plays an important role in land surface energy budget.It is also a key parameter related to land surface water and heat transfer processes.With the fast development of LST retrieval algorithm by remote sensing methods,LST products are provided by coarse resolution satellite observations such as MODIS and AVHRR,which are commonly used for global or regional study.However, it is still a big challenge for their application over mountainous area due to the high resolution demanded and terrain effect.In order to investigate the influences of topographic factors such as elevation,slope,and aspect on LST,a systematic study was conducted based on LST estimations in the typical mountain environment with Landsat 8 thermal infrared data.The results indicated that there are significant effects from topographic factors on LST distribution.Generally,LST decreases with the increase of elevation and slope. LST in south face usually is higher than that in north face.To discuss the scale problem over mountainous area,the estimated LST was analyzed at 1 km scale,close to MODIS LST spatial resolution,at the high mountain area and hilly area respectively.It was found that the LST at 1 km scale shows higher spatial heterogeneity with elevation and land cover at the complex terrain area.Therefore,high spatial resolution LST data is necessary for land surface water and heat transfer studies over mountain area to consider the impacts from topographic changes.