Abstract: Ginkgo biloba and Metasequoia glyptostroboides are two endemic tree species of China. In this paper, the decomposition rates of their litter placed under Ginkgo and Metasequoia forests in the parks in Beijing have been studied. The weight loss rate of the ginkgo litter placed under ginkgoes for 380 days was 55.63% and that for the metasequoia litter placed under metasequoias for 338 days was 53.39%. The exponential decay model was used and the annual decay rate of litter was estimated to be 0.771 g/(g·year) for the Ginkgo, and 0.824 g/(g·year) for the Metasequoia. Analysis of the chemical composition change in the litter showed that the changing tendency of the weight loss rate was in agreement with the net loss of the chemical composition in the litter. During the annual decmoposing process, the ratio of the carbon content and the nitrogen content of the litter decreased with the passage of time.