Abstract: Based on the data of fishery resources surveys in the Yangtze River estuary from 2012 to 2014, the spatial co-occurrence patterns and influencing factors of fish communities in that area were analyzed by using probability model and network analysis method. The results show that the fish community pattern in the Yangze River estuary is mainly the random co-occurrence of species. The influence of neutral elements was dominant in community construction, and the effect of random factors driven by environmental change on interspecific co-occurrence was greater than that of interspecific interaction. There was significant seasonal difference in the patterns of interspecific co-occurrence, which was mainly related to the seasonal changes of migratory marine fish and estuarine sediment fish. The seasonal replacement of fish species with high weighted degree and betweenness centrality might also have caused the high number of randomly associated pairs of species. It is also shown that Collikithys lucidus has strong ability to control information exchange within the community and is at the core of the fish community structure in the Yangtze River estuary.