Artificial grassland with higher productivity has developed rapidly in recent years in order to balance available pasture and stocking rates on the Qinghai-Tibetan Plateau. Soil nematodes are sensitive to environmental changes, which are important components of grassland ecosystems. However, little is known about the effects of the artificial grasslands with the different forage species on the diversity of soil nematode communities. Soil nematode communities in the natural grasslands (control) and artificial grasslands were investigated in July 2016. Four perennial grass (Elymus nutans Griseb., Elymus sibiricus L., Poa annua L., and Festuca ovina L.), one annual grass (Avena sativa L.), and one perennial legume (Medicago sativa L.) were selected. Forages were grown for four years in monoculture in this study. Soil nematodes were extracted from 50 g of fresh soil using Baermann funnels for each composite soil sample. The composite samples were comprised of three soil cores taken from the upper 0-15 cm soil. Soil nematodes were identified into 2 classes,8 orders,32 families,and 58 genera. The results showed that:(1) the average nematodes abundance was 1754 ind./100 g dry soil, ranging from 949 ind./100 g dry soil in the M. sativa to 3267 ind./100 g dry soil in the A. sativa. (2) The total abundances, taxonomic richness, Shannon diversity index of the soil nematodes communities, and the abundances of herbivores and omnivores-predators were significantly higher in the A. sativa grasslands compared to the natural grasslands. However, no significant difference was observed in the total abundances and diversity of the nematode communities and the abundances of fungivores, bacterivores and omnivores-predators between the rest artificial grasslands and natural grasslands. (3) The abundances of the soil nematode communities and each trophic group differed significantly among the different artificial grasslands, with the maximum values occurring in the A. sativa grasslands. (4) Redundancy analysis results showed that soil total K, C/N, total P and available K were the important factors affecting the composition of the soil nematode communities. The results suggested that establishing artificial grasslands with changes in plant communities and soil physico-chemical properties led to the change of soil nematode communities on the Qinghai-Tibetan Plateau, and the abundances and diversity of soil nematode communities were significantly increased by planting A. sativa. Given the vulnerability of ecological environment on the Qinghai-Tibetan Plateau, the changes in soil nematode communities depicted here indicate that underground process should be further studied before the area of artificial grasslands has been greatly increased.