Abstract: In order to reveal the distribution characteristics and influence factors of alpine steppe ecosystem vegetation C/P in Tibetan plateau, taking alpine steppe ecosystem in Tibetan Plateau as the abject, the vegetation C/P distribution characteristics and its influence factors were researched, based on the methods of field investigation combining with laboratory analysis. The results showed that: the average leaf N/P of 19 grassland type plants of alpine steppe in Tibetan Plateau was 204.53, the coefficient of variation (CV) was 35.72%. And the average root system C/P was 226.29, the CV was 27.93%. N/P appeared lower in east and west and higher in the middle part of Tibetan Plateau as a macrocosm tendency with distribution characteristics of staggered pattern. The key environmental influence factors of plant leaves C/P were: average annual temperature, average temperature in the coldest month, precipitation during the period from June to September, soil bulk density of depths from 0 cm to 10 cm, soil water content of depths from 10 cm to 20 cm, soil content of available K and water-soluble carbon and total nitrogen and total N, P and K. And the key environmental influence factors of plant roots C/P were average temperature in the coldest month, ≥10℃ accumulated temperature, average annual precipitation, aboveground biomass production, soil pH, soil organic matter and soil content of total K, P and carbohydrate.