Abstract: Aspect is an important topographical factor that affects illumination, temperature, and soil nutrients, all of which affect the composition and distribution of plant species. In this study, we evaluated the effect of aspect on the soil nutrient characteristics and on the composition and spatial distribution of plant communities in an alpine meadow in the northeast margin of the Qinghai-Tibet Plateau. The dominant and subdominant species in grassland communities were Leymus secalinus, Stipa krylovii, and Koeloria cristata (Gramineae) on sunny slopes and Kobresia humilis and Kobresia capillifolia (Cyperaceae) and Melilotoids ruthenica var. inschanica (Leguminosae) on shady slopes. The herbage height, α-diversity index, and number of plant species in grasslands were greater on shady slopes than on sunny slopes, while the β-diversity indexes of grasslands were similar between shady and sunny slopes. The plant life-form spectrum both on sunny and shady slopes mainly consisted of hemicryptophytes and geophytes, accounting for 89% and 71% of the total number of species, respectively. There were more annual and biennial plants and hemicryptophytes on sunny slopes than on shady slopes, but more hemicryptophytes on shady slopes than on sunny slopes. There were similar numbers of geophytes on sunny and shady slopes. The plant families contributing to total biomass in grassland communities on sunny slopes were Gramineae (78.3%)>Cyperaceae (8.3%)>Asteraceae (6.4%)>others (7%); and to grassland communities on shady slopes were Cyperaceae (54.3%)>Leguminosae (16.4%), Gramineae (14.8%)>Polygonaceae (5.3%), Asteraceae (4.6%), and others (4%). For all of the plant families except for the Asteraceae, the contribution to total biomass differed significantly between sunny and shady slopes, but the contribution to total aboveground biomass was similar between sunny and shady slopes. The nitrogen content in the 0-20 cm soil layer was higher on the shady slope than on the sunny slope, while the phosphorus, potassium, copper, and zinc contents in the 10-20 cm soil layer were higher on the sunny slope than on the shady slope. The soil temperature in the 0-30 cm layer was higher on the sunny slope than on the shady slope, whereas the water content in the 0-40 cm soil layer was higher on the shady slope than on the sunny slope. Together, these results show that aspect plays an important role in the composition of vegetation communities and in the physical and chemical properties of soil in alpine meadows.