Abstract: The survey for the HEIFE (Atmosphere-Land Surface Processes Experiment at Heihe River Basin. Western China) is given in this paper. Somebasic subjects for land-surface processes in arid area are studied. They are: (i) The general characteristics about the energy budget on ground suface in arid area are analysed. The results show that the sensible heat flux on the surface energy budget is in majority. the latent heat flux may be neglected. (ii) The parameterizations of the land surface processes are studied. The influence of atmospheric stratification stability on the turbulent transfer of energy and matter must be considered in parameterizations of land surface processes in arid area. (iii) The interaction, which is a special phenomenon in arid area. between oasis and its desert circumstance is studied. The "coldisland effect" phenomenon in oasis and the "inverse humidity" phenomenon in desert near oasis are a result of the interaction between them. The results should improve the understanding of processes at the land surface in arid area.