Abstract: Soil nematode is an important part of the soil micro-food web. In order to study the seasonal dynamics of soil nematode community abundance and diversity along the altitude gradient, and to understand and compare soil nematode diversity at different temporal and spatial scales, in this study, six altitudes（750, 830, 950, 1 100, 1 300, and 1 420 m） were set in natural larch forests in the Oakley Mountain in the north of the Greater Khingan Mountains in China, and Illumina MiSeq sequencing method was used to explore the community composition and structural characteristics of soil nematodes in 0-10 cm soil. The results showed that the soil nematode community diversity in the cold temperate zone of high latitude showed a monotonically decreasing pattern along the altitude gradient in different seasons. One phylum, three classes, 11 orders, and 53 genera were identified and bacterivores were the dominant trophic groups at each altitude and season. The effect of altitude gradient on soil nematode community structure was stronger than that of seasonal variation. Sobs and Faith’s phylogenetic diversity showed a downward trend with the increase in altitude. Soil pH, soluble organic carbon, and soluble organic nitrogen were significant factors affecting the altitude distribution of soil nematodes in different seasons.