Abstract: The community structures of zooplankton in the coastal waters of Qingdao and their adjacent waters were characterized based on the samples collected in December 2015, January 2016, April 2016, June 2016 and September 2016. The species composition, abundance, dominant species, biodiversity and the seasonal variation of the zooplankon were analyzed. A total of 44 species and 17 taxa of zooplankton larvae were identified, mainly consisting of warm temperate species, eurythermal speices and euryhaline species. The seasonal variation of dominant species was obvious. Paracalanus parvus, Calanus sinicus and Corycaeus affinis were the dominant species in the study area throughout the year. The abundance of zooplankton peaked in June (8662.0±8890.0) ind./m³ while the lowest of that showed in December (426.9±148.5) ind./m³ with the annual average of (3059.2±3012.4) ind./m³. In contrast, the Shannon-Weiner diversity index of December samples was the highest one among seasons while that of June was the lowest. Cluster analyses grouped zooplankton into three communities, including the Jiaozhou bay community, the South Yellow Sea coast community and the South Yellow Sea central community. The zooplankton community showed a signifcant seasonality, and it was clusterd to three gourps: the winter group (December-January), the spring-early summer group (April-June) and the autumn group (September). The primary environmental factors affecting zooplankton community were bottom salinity and depth.