Abstract: On the basis of gradient data of the surface layer obtained from four sets of Automatic Weather Station(AWS)installed in Lhasa,Nagqu,Xigazê and Nyingchi on the Tibet an Plateau from July 1993 to March 1999 according to the project of PRC-Japan Asian monsoon mechanism cooperative research,the seasonal surface roug hness lengths and diurnal bulk transfer coefficients at each station are estimated.Then the surface fluxes of momentum,sensible and latent heat are calculated by using bulk formulas.Moreover,the composite characteristics in diurnal and monthly variation of surface fluxes are emphatically analyzed in this paper.