Poyang Lake is an important overwintering site for migratory birds in Asia. Poyang Lake National Nature Reserve (PLNNR) is a hot spot for birds inhabiting or overwintering at Poyang Lake. Hitherto, limited checklist of bird species has been available. In order to investigate the bird diversity and avifauna of PLNNR, complete species checklist was strictly checked according to systematic analyses of species records from multisource. Fifty-seven species were newly recorded based on the previous study of 330 bird species. Six previously reported species were removed. We finally recorded 381 bird species, belonging to 18 orders 64 families, accounting for 27.8% of bird species in China; 205 species (53.8%) are Palearctic, 83 (21.78%) Oriental and the rest 93 (24.42%) are cosmopolitan. Ten species are listed in grade I national key protected animals, and 56 species are designated in grade II national key protected animals. Four species (Bambusicola thoracicus, Turdus mupinensis, Garrulax poecilorhynchus and Parus venustulus) are endemic to China. Breeding birds account for 201 species (52.8%) of the nature reserve bird species; 53 belong to Palearctic, 78 to Oriental Realms and the rest 70 cosmopolitan. The Oriental Realms species are dominated and the results are in accordance with features of Jiangxi avifauna. The G-F index of birds of PLNNR is 0.873, higher than other nature reserves in Jiangxi Province. The study will contribute to the management and conservation of birds in PLNNR.