Abstract: In this paper, the contents of protein, fat and starch were compared among Kobresia humilis plants grown at different altitude in Qinghai-Xizang plateau (Daban Mt, 4,000 m a.s.1; Jinyang Mt,3,800 m a.s.1;Haibei station, 3,200 m a.s.1;Xining,2,200 m a.s.1). The results show that some biochemical component in aboveground and belowground tissues of the plants tended to increase with increasing altitude. As compared with those plants in Jinyang Mountain, Haibei Station and Xining, on average, the plants grown at Daban Mountain had a higher protein content by 9.9% ,17.3% and 39.4%, a higher fat content by 7.5% ,77.8% and 106.8%, and a higher starch content by 2.4%, 21.6% and 32.7% ,respectively. It is clear that altitude had effects on the seasonal changes of the contents of some biochemical components.The results suggest that the stronger frost resistance of the plants located at a higher altitude are associated with their stronger synthesis of the protein, fat, starch and related substances.