Abstract: This paper reported the food pattern，food preference index and natritional componant of food itemsJ and analysed the relation between the food quality and the food selection．PIateau pikas mostly ate dicotyledon leaves．Comparison of diet composition with forage availability indicated the food selective degree on each food item for plateau pikas．PIateau pikas strongly preferred Elymus nutans，Oxytropis ochrocephala and Potentilla nivea, Contents of nutrient component in the three food items were changed markly monthly．Wefound positive correlations between dietary percents of food item sand those for water，crude protein，sodium (Na)and phosnhorus(P)contents，and negative correlations between dietary percents and those for fat，fibrel potassium (K)，calcium (Ca)and magnesium (M g) contents．Multiple regressive techniques revealed that only the relationships with dietary percents and phosphorus (P) content remained singnificant wheneffects of other nutrients were removed．Those correlations and regressions between those nutrients and dietary percents were diffcrrents(Table 5 and Table 6)．Those results above support to the hypothesis：the forage availability and found quality decide food selection．

Key words: Herbivorous small mammalsI Nutritional ecology, Plateau pika(Ocherulae), Food selection, Food quality

摘要： 本文报道了高原鼠兔(Ochotona curzoniae)的食物模式，食物选择指数及食物项目的营养成分，并探讨食物质量与食物选择的关系。高原鼠兔主要选食双子叶植物叶片。食物组成与饲料可利用量的比较分析，揭示出高原鼠兔对各种食物项目的选择程度。在排除其它营养因子的作用后，复回归分析的结果表明，食物百分率与磷含量之间具有显著的正相关。各种食物项目不同营养成分与食物百分率之间相关关系不一致。从而进一步验证了食物选择击定于饲料可利用量和食物质量的假设。

关键词: 植食性小哺乳类, 营养生态学, 高原鼠兔, 食物选择, 食物质量