This study aims to understand the succession characteristics of zooplankton communities during dramatic water level fluctuations in Poyang Lake. During the drastic fluctuations in water levels of Poyang Lake in the summer, and on June 24, July 7 and August 27, 2012 when the water level dropped and approached 17.6 meters, four sampling points were established in a shallow dished sub-lake in Poyang Lake National Nature Reserve for the survey of zooplankton. A total of 65 species of zooplankton, including 52 species of rotifers, seven species of cladocerans and six species of copepods, were found during the study period. The zooplanktons were mostly the wide-temperature and mesophilic species of the planktonic type. The one-way analysis of variance revealed significant differences in zooplankton density and biomass within the three-month period (P<0.05). The density of zooplankton in July (1030.17 ±68.18 ind./L) was significantly higher, when compared to that in June (325.16 ±41.60 ind./L) and August (203.79 ±24.91 ind./L). Furthermore, the biomass of zooplankton in June (0.56 ±0.04 mg/L) was significantly lower than that in July (1.22 ±0.11 mg/L) and August (0.99 ±0.11 mg/L). The clustering of zooplankton communities by Bray-Curtis similarity measure and self-organizing maps revealed that the zooplankton was clearly divided into three communities:June community, July community, and August community. The Monte Carlo test revealed that water temperature, conductivity, turbidity and dissolved oxygen were significantly correlated with zooplankton community structure changes (P<0.05). The typical correlation analysis revealed that there was significantly positive correlation between zooplankton community and chlorophyll-a content in June. The water temperature and zooplankton community had a significant positive correlation in July. Furthermore, there were significant positive correlations between the zooplankton community and water depth, conductivity, turbidity and dissolved oxygen in August (P<0.05). Asplanchna girodi, which was the dominant species in the three-month period, was positively correlated with the chlorophyll-a content (P<0.05), but was negatively correlated with water temperature, pH and dissolved oxygen (P<0.05). The present study revealed that the zooplankton community structure exhibited a significant succession between months. Furthermore, the density of rotifers gradually decreased, and the density of cladocerans and copepods gradually increased. Moreover, the water level fluctuations caused changes in environmental factors, which had an important impact on the community succession of zooplankton.