Alpine vegetation of Qinghai-Tibetan plateau is greatly related to yak livestock grazing during thousands of years (Miehe et al., 2009). Their floristic composition is extremely rich. However, their structure and functional organization are still poorly investigated. Chengdu Institute of Biology has been studying ecosystems of Mt. Kaka for some years. Soils, microclimatic conditions, structure of vegetation in relation to snow cover are now described, but the fine estimations of biomass structure and functional traits and the classification of Tibetan alpine vascular plants functional types have not yet been done timely..Thus, our study is to investigate the structure and function of common alpine plant communities under yak grazing and without grazing (at fenced plots)..The main questions are:.1) to estimate aboveground biomass in typical alpine plant communities of the Mount. Kaka;.2) to distinguish functional types of Tibetan alpine plants on the base of leaves properties, seed productivity, vegetative mobility and life forms according to Ch. Raunkiaer and I.G. Serebryakov classifications;.3) to compare functional structure within Tibet plant communities (grazed and without grazing) and with functional structure of alpine (Nortwestern Caucasus, Russia) and subarctic (Abisko, Sweden) communities concerning plant species abundance in terms of biomass; .4) to estimate impact of grazing on the functional traits changes of a set of most common plant species..The study area is situated on Mount Kaka (32°59' N, 103°40' E) of the Minshan Range on the eastern Tibetan Plateau, at elevation of 3400-3900 m. Besides, we will investigate meadow, located at upper part of forest belt at ca. 3400 m a.s.l. with Potentilla anserina (ca. 40% of cover), Cerastium furcatum, Carex enervis and a range of annual species..We establish 20 plots at these communities grazed and fenced. Aboveground biomass from every plot will be sampled and separated by species. Biomass structure and parameters of leaves will be studied. In order to estimate abundance of plants with various functional types within a range of Tibetan alpine plant communities according to their biomass, we estimate leave area, thickness, water content, and specific leave area and measure the mass of 100 seeds for these species..We expect that in fenced communities the abundance of broad-leaved species with erosulate shoots should increase, as well as total biomass. The following comparison of functional structure of Tibetan grazed and ungrazed alpine plant communities with the communities of temperate mountains of Caucasus and subarctic mountains at Abisko, with data derived by the standardized methods, can reveal geographical and grazing-dependent patterns in pasture ecosystems, and common suits of plant traits which cause adaptations of vascular plants to permanent grazing impacts. This work allows us to predict the structure and productivity of alpine ecosystems under different grazing activity.