Regional distribution regularities on soil C/N have been a hot topic in recent years, but currently there were few studies reporting the soil C/N distribution in alpine steppe ecosystem under different vegetation zones in Qinhai-Tibetan plateau. In order to reveal the spatial distribution characteristics of the soil C/N on the alpine steppe ecosystem in different vegetation zones, and to provide scientific basis for understanding a regional specific acclimation of vegetation to climate change in Qinhai-Tibetan plateau, we surveyed the soil C/N of alpine steppe ecosystem under different vegetation zones. Collectively, we sampled 67 sampling points. The soil C/N of the alpine steppe ecosystem in Qinhai-Tibetan plateau was also compared with that of 14 natural transects in areas outside the plateau. The results showed that: (1) Along the horizontal direction in Qinhai-Tibetan plateau, C/N appeared higher in northwest and lower in southeast. The higher C/N appeared mainly in the regions with a concentration in the hinterland of northern part of Tibetan Plateau and in the lake basin region of the northern foot of Himalayas. There were significant differences of C/N among different grassland types and natural transects. (2) Along the vertical direction of the soil profiles from aboveground to underground, it could be divided into 5 types of low-high-low, from high to low, from low to high, high-low-high-low and high-low-high of C/N distribution patterns among different grassland types and natural transects, and there was significant difference of C/N between the surface soil depths from 0 cm to 20 cm and the deeper soil depths from 30 cm to 40 cm. (3) C/N was significantly and positively correlated with average temperature in the coldest month, average annual evaporation, average annual relative humidity and soil total nitrogen content, respectively. The C/N was significantly correlated with average annual sunshine hours, average annual temperature and soil available K content negatively, respectively. The effect magnitude of environmental factors on the C/N followed an order of average annual relative humidity > average annual sunshine hours > average temperature in the coldest month > average annual temperature > average annual evaporation > soil total nitrogen content > soil available K content. Due to the complex spatial distribution along both horizon and vertical directions, the research work of soil C and N and the relationship between C and N of the alpine steppe ecosystem in Qinhai-Tibetan plateau are highly important. Conclusively, climate is the most important environmental influence factor on the soil C/N of alpine steppe in Qinhai-Tibetan plateau. Future research work should focus on the relationship between soil C/N and climatic factor, especially the relationship between soil C/N and moisture factor.