Based on the observed data in 2007 from Xidatan and Tanggula monitoring Sites (laid by Cryosphere Research Station on Qinghai\|Xizang Plateau, CAS), surface energy budget components of the two sites with different vegetation types were calculated. Their seasonal variation characteristics and the mean factors affecting them were analyzed. The results indicate that seasonal variation of net radiation is significant in this region, with the maximum in summer and the minimum in winter, and the solar elevation angle and underlying surface condition are the main influencing factors. Similar trend can be seen in soil heat flux. The sensible heat flux reaches the maximum in spring, followed by that in summer, and in winter it reaches the minimum, tightly depending on monsoon, thawing and freezing processes, underlying surface conditions and the variation of net radiation. However, latent heat flux, mainly constrained by precipitation and surface soil moisture, has the maximum in summer and the minimum in winter. In addition, energy between land and atmosphere is exchanged mainly in the form of sensible heat transfer during winter and spring, whereas latent heat flux turns to be dominant in summer and autumn.