Litter decomposition is an important ecological process in global carbon (C) and nutrient cycling. This process is mainly determined by three factors of interaction, namely, chemical (physical and chemical properties of litter), physical (climate and environment), and biological (microorganisms and invertebrates involved in the decomposition of litter) factor. Under the same climate and site environment, the quality of litter is the internal factor that restricts decomposition. This study aims to investigate the decomposition rate and dynamic characteristic difference of carbon, nitrogen, phosphorus release from the litter of Phragmite, Triarrhena lutarioriparia, Carex. cinerascens Kükenth in Poyang Lake wetland, using decomposition bag technique. The results showed that there were significant differences of the dry mass remaining rates, decomposition rates, and carbon relative return index (CRRI), nitrogen relative return index (NRRI), phosphorus relative return index (PRRI) between three types of plants litter within 0-150 d. The decomposition rate of Phragmite was the highest, followed by Carex. cinerascens litter, and decomposition rate of Triarrhena lutarioriparia was the smallest. After 150 days of decomposition, the dry mass remaining rates of Phragmite, Triarrhena lutarioriparia Carex. cinerascens were about 56.57%, 67.99%, and 60.88%. The CRRIs of the three plants were 57.44%, 34.58% and 41.75%, the NRRIs of them were 50.71%, -22.66%, and 23.18%, and the PRRIs of them were 88.91%, 79.27% and 85.63%, respectively. The simulation results of Olson negative exponential model estimated that it would cost 184, 249 and 210 days respectively for decomposing 50% of Phragmite, Triarrhena lutarioriparia, Carex. cinerascens litter and about 759, 1078 and 908 days for 95% of them. The C, N, P of Phragmite and Carex. cinerascens litter showed a net release pattern within 150 days, while the C and P of Triarrhena lutarioriparia litter also showed a net release pattern, but N always showed a net accumulation pattern. Our studies showed that the plant species and the physical and chemical properties of litter had a strong regulatory effect on the decomposition and the release of nutrients. Our future studies should consider the decomposition process of different species litter mixing and the microbial factors in the decomposition process, so as to reveal the regulation mechanism of plant community species diversity and microbial activities in wetland biogeochemical cycle. In order to provide a renewed understanding for the biogeochemical cycle of C, N, and P in Poyang Lake wetland, and to provide scientific basis for scientific management, protection and restoration of Poyang Lake wetland.