We examined the seasonal distribution of the functional groups of ground-active arthropods by pitfall traps in Lycium. barbarum plantations in oasis of Ningxia in spring, summer and autumn of 2018. The relationship between the abundance and richness of functional groups and environmental factors were examined. All the results showed that: (1) The functional groups of ground-active arthropods of L. barbarum plantations included phytophagous, predatory, sacrificial and omnivorous animals, accounting for 6.31%, 86.75%, 2.01% and 4.86%, respectively. It was suggested that the predatory animals dominated the ground-active arthropod communities. (2) The abundance and biomass of phytophagous arthropods were significantly higher in spring than in autumn, with the intermediate values observed in summer; the richness of phytophagous arthropods was significantly higher in summer than in autumn, with the intermediate values observed in spring. The biomass of predatory arthropods was significantly higher in summer and autumn than in spring; whereas there was no significantly different in the abundance and richness of predatory arthropods between the three seasons. Likewise, there was no significant difference in the abundance, biomass and richness of sacrificial arthropods between different seasons. Nevertheless, the abundance and richness of omnivorous arthropods was significantly higher in spring than in summer, with the intermediate values observed in autumn; whereas there was no significant difference in the biomass of omnivorous arthropods between different seasons. (3) There was positive correlation of the abundance of predatory arthropods with soil moisture; there was positive correlation of abundance of sacrificial arthropods with soil total phosphorus, and there was positive correlation of abundance of omnivorous arthropods with soil total nitrogen. However, there was negative correlation of abundance of phytophagous arthropods with soil moisture, and there was negative correlation of abundance of omnivorous arthropods with soil temperature and soil total carbon. (4) The partial RDA results showed that soil moisture were the key factors forcing the distribution of functional groups of ground-active arthropods between seasons. In conclusion, there was unique different distribution of functional groups of ground-active arthropods in L. barbarum plantations along with the seasonal timing in arid oasis of Ningxia province, and the difference of functional diversity is little. It was suggested that there was a sensitivity of abundance and richness distribution of each functional group, whereas there was a relatively stable distribution of functional diversity across seasons.