基于Noah陆面过程模式，利用内蒙古荒漠草原陆-气通量长期定位观测资料，模拟了地表反照率日变化对该荒漠草原感热和潜热通量的影响。结果表明，地表反照率的日变化将改善Noah陆面过程模式对内蒙古荒漠草原感热通量的模拟，但对受水分制约的潜热通量的改善效果不明显，表明准确地模拟地表反照率的日变化对模拟稀疏植被的感热通量至关重要。“,”Diurnal variation of land surface albedo was coupled into Noah land surface model, and its effect on sensible and latent heat fluxes in desert steppe of Inner Mongolia was discussed based on the long- term flux data over the desert steppe in Inna Mongolia. Results indicated that the variation of net radiation in the desert steppe directly affected changes of sensible heat flux and potential evaporation, but had no ob- vious influence on ground heat flux. In the dry desert steppe, the observed solar radiation was mainly par- titioned into sensible heat flux, and only smaller part was converted into latent heat flux. Therefore, Noah land surface model could improve the simulation of sensible heat flux with the actual diurnal land surface albedo. The standard error and bias of the simulated sensible heat flux reduced obviously, and Nash-Sut- cliffe index was close to 1. But the improvement of the latent heat flux was not obvious, which was re- stricted by water. However, since the soil moisture was the main part of this surface albedo function over the desert steppe and Noah land surface model produced too much soil moisture, the simulated surface al- bedo was smaller than the observations, which resulted in the larger values of the simulated sensible heat flux. It implied that diurnal change of land surface albedo plays a very important role for the accurate sim- ulation of the sensible heat flux of sparse vegetation.