[Objective] In this study, a tract of Tsuga dumosa forest typical of the Garongla Mountain, Motuo County, Southeast Tibet was taken as research object. The purpose of this study was to investigate structure and diversity of the soil nematode community in the Tsuga dumosa forest ecosystem in this region and their relationships with soil properties, and stability and succession of the ecosystem by analyzing environmental indicators and functions of the soil nematode community. This study is expected to be of important scientific significance in unveiling diversity laws of the soil nematodes in the Tsuga dumosa forest ecosystem in Southeast Tibet, discussing interactions and correlations between the evolution processes underground and aboveground, and learning roles of the soil nematode community in subalpine/alpine forest soil ecological processes.[Method] In September 2017, four sample plots were set up different in plant community and topography. Soil sampling points (at least 5 points) were specified in each sample plot randomly in distribution and soil samples were collected from 5 soil layers, 0-5 cm, 5-10 cm, 10-15 cm, 15-20 cm and 20-25 cm, at each sampling point with a soil drill 7 cm in inner diameter, and then blended together into one, separately. Nematodes in the soil samples were separated with the shallow basin method, observed under stereomicroscope for identification till the genus level and characterized by species composition, individual density, diversity index and functional index for analysis of structure and diversity of the soil nematode community. The soil samples were also analyzed for physical and chemical properties with the conventional methods, and redundancy analysis and linear correlation analysis was performed of the data for relationships with the nematode community.[Result] Results show that soil nematodes in the soil under Tsuga dumosa forest in Mt. Galongla could be sorted into 5 orders, 29 families and 34 genera, averaged to be 278 individuals·100 g^-1 dry soil in density and did not vary much between soil layers. In the community Tylencholaimus and Leptonchus were the dominant genera and fungivorous nematodes were the most important nutritional group. Soil organic matter was decomposed mainly by fungi. Redundancy analysis (RDA) and linear correlation analysis shows that readily available potassium, organic matter, total nitrogen and total potassium are the major factors affecting the soil nematode community and its relationship with soil physical and chemical properties, and readily available potassium is the most important one. A significant and positive relationship was found between nematode density and soil water content. Uneven distribution of soil water may be one of the important causes for the variation of soil nematodes community in density with the habitat in the hemlock forest in Mt. Garongla.[Conclusion] Soil organic matter is decomposed mainly by fungi. The Tsuga dumosa forest ecosystem in Mt. Garongla is high in maturity and in a relatively stable state. The content of readily available potassium in the soil significantly affects number and diversity of the nematodes in the community. Organic matter, total nitrogen, hydrolyzed nitrogen and available phosphorus are also factors affecting number of the nematodes. Soil water content is one of the important environmental factors that affect species composition of the soil nematode community and number of the nematodes in the soil under Tsuga dumosa Galongla forests.