A simulation experiment was conducted to study the effects of ultraviolet B (UV-B) radiation on the leaf litter chemistry and subsequent decomposition of Elaeocarpus sylvestris, a common tree species in China subtropical zone. The leaf litter was derived from E. sylvestris seedlings, and exposed to elevated (10% enhancement) UV-B radiation and ambient UV-B radiation for one year. Elevated UV-B radiation increased the leaf litter N content significantly, but decreased the leaf litter C, P, K, and lignin contents and C∶N and lignin∶N ratios. The decomposition of the leaf litter derived from E. sylvestris seedlings and exposed to elevated UV-B radiation had no significant difference with that in ambient UV-B treatment. During the first 10 months of decomposition, the N enrichment occurred, and the enrichment degree was significantly higher in treatment ambient UV-B radiation than in treatment elevated UV-B radiation. The release of P and K occurred during litter decomposition, but had no significant difference between the two treatments.