Soil fauna are crucial decomposers in terrestrial ecosystem. The structure and diversity of soil fauna may vary with changes in decompsition stages and litter quality during litter decomposition, but how the compositon and structure of soil arthropod vary during litter decompostion in subtropical forests remain poorly understood. In this study, we conducted a four-year litter decomposition experiment (2011-2015) to explore the compositon, structure and diversity of soil arthropod during litter decomposition. Two dominant tree species with contrasting leaf traits (coniferous vs. broadleaf) were used for field incubation in a subtropical forest of Sichuan Basin, southwestern China. Fresh senesced litter was collected using 1m×1 m litter traps in our study site between September and October 2011. The litter contained a coniferous species (Cryptomeria fortunei) and a broadleaf species (Quercus acutissima). The litter samples were air-dried for 2 weeks at 25℃ and 10±0.05 g was placed in 20 cm×20 cm nylon litterbags. A total of 130 litterbags (11 sampling times×5 plots×2 tree speices+20 spare litterbags) were carefully placed on the forest floor in late November 2011. A total of 11 sampling events were performed during our four-year litter decomposition study. Throughout the four years of decomposition, 3855 individuals and 51 families of soil arthropod were extracted from the litterbags. According to the individual proportion and composition of the taxa, Isotomidae and Onychiuriclae were the two numerically dominant taxa regardless of tree species during the decompositon. The individual density of the soil arthropod in the broadleaf litter showed an increasing trend with the decomposiotn proceeded and reached the maximum level at 1079 days of decomposition, and that in the coniferous litter increased to the maximum level at 156 days of decomposition and then rapidly decreased. The family richness of the soil arthropod in both the broadleaf and coniferous litter had a similar dynamic during litter decompostion. The fungivorous and saprophyte soil arthropod were the highest and least proportion of funcational groups of soil arthropod during the decompostion, respectively. As the decompsition proceeded, the proportion of the phytophaga soil arthropod decreased and that of the fungivorous soil arthropod increased. The NMDS analysis showed that the composition of soil arthropod community had sigificant difference between the broadleaf and coniferous litter. The cluster analysis indicated that the similarityof soil arthropod community structure between the broadleaf and coniferous litter continued decrease during the study. The results suggest that the composition, structure and diversity of soil arthropd are affected by litter type during litter decomposition in subtropical forests.