In order to explore the relationships between the vegetation and environmental factors in Bayanbulak Swan Lake alpine wetland, vegetation survey was conducted and environmental factors, including water table (WT), total nitrogen content (TN), soil organic carbon(SOC), and total phosphorus (TP), were measured in 2014 and 2015. The results showed that a total of 35 plant species belonging to 19 families and 27 genera were identified in Bayanbulak Swan Lake alpine wetland. One-way ANOVA revealed that species composition and richness were significantly affected by the surface water level. Species richness and Shannon-Wiener index increased, and the Pielou index decreased with the decreasing of surface water level. The RDA and partial RDA analyses revealed that four environmental variables totally explained 67.9% of total variations in species composition, of which the gross effects of WT and TN on species composition were significant and the net effect of TN was also significant. However, the gross and net effects of SOC and TP was not significant. Overall, our results indicate that WT and TN are two important determinants of the vegetation composition and its distribution in Bayanbulak Swan Lake alpine wetland.