Abstract: By using litterbag method, a 190day incubation experiment was conducted to study the decomposition rates and the release dynamics of C, N, and P of the litters from three dominant species (Taxodium ascendens, Echinochloa cruspavonis, and Alopecurus japonicas) in T. ascendens forest in Dalian Lake, Shanghai. In the meantime, the quantity of the litters in the T. ascendens forest was measured by using collection container. In the forest, the annual production of T. ascendens litters was 5.70 t·hm^-2, being the primary source of the litters in the forest. The litter decomposition rate (dry mass loss rate) was in the order of A. japonicus > E. cruspavonis > T. ascendens. During the experimental period, the C content of the three species litters decreased significantly, while the N and P contents had somewhat increase in T. ascendens litters but not in E. cruspavonis and A. japonicus litters.