Abstract:A field survey was conducted to investigate the community composition and seasonal dynamics of ground-active arthropods in Reaumuria soongorica shrubbery land in Urat Desert Steppe. In order to determine seasonal changes, pitfall traps were used to collect specimens in spring, summer and autumn in 2018. The results showed that: (1) there were 560 individuals of ground-active arthropods captured in the three seasons, belonging to 23 families and 10 orders. Among them, the dominant group was Tenebrionidae in spring, Tenebrionidae and Formicidae family in summer, and Tenebrionidae in autumn, accounting for 51.54%, 59.11%, and 64.88% of the total individual number, respectively. There were 8 common groups in spring and summer, and 10 common groups in autumn, accounting for 43.08%, 37.33% and 32.68% of the total individual numbers, respectively. There were 7 rare groups in spring, 6 in summer, and 3 in autumn, accounting for 5.38%, 3.56% and 2.44% of the total individual numbers, respectively. (2) The ground-active arthropods that accounted for more than 10% of total biomass were the Tenebrionidae family, accounting for 88.59%, 72.56% and 80.90% of the total biomass of the community in spring, summer, and autumn, respectively. Ground-active arthropod biomass between 1% and 10% accounted for 9.76%, 25.51%, and 17.78% of the total community biomass in spring, summer and autumn, respectively. The groups with the proportion of biomass < 1% accounted for 1.62%, 1.94% and 1.32% of the total community biomass in spring, summer and autumn, respectively. (3) There were significant differences in density, group numbers, Shannon-Wiener index, and Simpson index of ground-active arthropods with seasonal dynamics (P<0.05), with significantly higher values in summer than in spring or autumn. (4) The results from RDA and Spearman correlation analysis showed that rainfall, temperature, soil moisture, soil pH and conductivity, and soil particle size were important factors influencing the seasonal distribution of ground-active arthropods. It was concluded that the ground-active arthropods were dynamic along with the seasonal timing in Reaumuria soongorica shrubbery land in Urat desert steppe. There was markedly greater ground-active arthropod diversity obtained in summer. The environmental factors including rainfall, temperature, soil moisture, soil pH and conductivity, and soil particle size indicated significant effects on the individual distribution of ground-active arthropods.