Abstract. Sunlight, as a main driver of terrestrial ecosystem process, not only runs the synthesis, but also the decomposition. In nature, soil surface might be exposed to different light intensities, but the decomposition as affected by light intensity remains unknown. A shading experiment was conducted to simulate the effects of different light intensities on decomposition of foliar litter in a subtropical region of western China. Over two-year incubation, foliar litter mass lost 54.46-100% depending on tree species and light intensities, and 37.21-80.58% of mass losses occurred in rainy seasons. Light intensity gave strong effects on litter mass loss, but the effects varied with tree species and season. Shading treatments promoted the litter decomposition in the dry seasons, but inhibited the decomposition in the rainy seasons. Light intensity, tree species, and their interactions are the main factors regulating litter decomposition in subtropical regions.