Abstract: 【Objective】 The study was aimed to investigate the effect of UV-B radiation on litter decomposition and nutrient cycling in terrestrial ecosystems.【Method】 The decomposition rate and nutrient release of Reaumuria songarica and Salsola passerina litters in an arid desert were studied using the decomposition bag method. The decomposition bags were exposed to natural light and filtered UV-B radiation.【Result】 The decomposition of desert shrub litters varied with decomposition time,species,and UV-B radiation intensity. As the decomposition time increased,the mass residual rates of both litters decreased. After 12 months of decomposition,the mass residual rates of R. songarica and S. passerina litters under UV-B radiation filtration were 7. 22% and 2. 74% higher,respectively,compared to those under natural light. The decomposition rate of R. songarica litters under natural light was significantly higher than that under UV-B radiation,while the difference in S. passerina litters was not significant. Under both radiation conditions,the carbon and nitrogen contents of the litters showed a decreasing trend with increasing decomposition time,while the phosphorus content showed an increasing trend. Carbon,nitrogen,and phosphorus were released during decomposition under both natural light and UV-B radiation filtration. However,after 12 months of decomposition,the release rates of C,N,and P were higher under natural light. The litters exposed to UV-B radiation had higher levels of C,N,and P,and the release rates of C and P were significantly different from those under natural light.【Conclusion】 In conclusion,under the background of global climate change,UV-B radiation alters the decomposition process of desert shrub litters. UV-B radiation filtration inhibits the decomposition rate and carbon release of R. songarica litters,while promoting the carbon and nitrogen release of S. passerina litters.