Abstract: The diversity of waterbirds in a sample area within the Kangshan migratory bird nature reserve (Kangshan) and Duchang migratory bird nature reserve (Duchang) on the Poyang Lake was investigated using a direct count method between 2017 to 2019. A total of 159 701 individual waterbirds belonging to 48 species, 7 orders, and 12 families were recorded, including 37 species with 38 074 individuals in Kangshan and 41 species with 121 627 individuals in Duchang. Of the species identified, five are listed as China's first-class national protected animals including the scaly-sided merganser (Mergus squamatus), Siberian crane (Grus leucogeranus), hooded crane (Grus monacha), oriental white stork (Ciconia boyciana), and black stork (Ciconia nigra). Another five species are listed as second-class national protected animals. Variation in the distribution of national protected bird species and main bird groups was detected in Kangshan and Duchang, indicating that these two reserves have their own important role in bird conservation. A total of 10 dominant species were recorded in Kangshan and Duchang. Members of the Anatidae and Scolopacidae were the most abundant species. Between 2017 and 2019, eight dominant species belonging to the Anatidae and Scolopacidae were recorded in Kangshan and only three dominant species belonging to the Anatidae were recorded in Duchang. The species number, number of individuals, and community dominance were lower in Kangshan than in Duchang, but the diversity index and evenness index were higher in Kangshan than in Duchang. This difference can be explained by the micro-habitat variation between the two regions. Based on the differences in waterbird species in the two reserves, it could be concluded that Kangshan and Duchang have complementary advantages in ecological functions that are important for the conservation of national protected waterbirds and dominant species.