The interactions between fish species and their roles in the ecological network on structuring the fish community is a matter of great concern not only for understanding the species coexistence, but also for the multispecies fishery management and conservation at the community level. The data from the bottom trawl surveys of eight cruises in Leizhou Bay waters northern South China Sea during 2016 and 2018 were applied to analyze how the species interactions (interspecific competition in limited resources and space) affected the stability of fish community structure in seasons and years. Combining theories on spatial niche overlap and the ecological network modeling, six indicators such as the weighted clustering coefficient (C), weighted average path length (A), connectance (Co), degree (K), weighted node strength (Si), and locally weighted clustering coefficient (Ci) were respectively applied to measure the degree of community aggregation, the overall energy transfer efficiencies between species, interspecific connectivity, the degree of directly interspecific associations, the intensity of species interactions, and the degree of local aggregation between species. And then we analyzed the importance of species interactions in structuring fish community of Leizhou Bay waters. The results showed that:①the network of species interaction which formed by spatial niche overlap of fishes varied more widely in seasons, but comparatively minor between years, including 58-122 kinds of fishes, and 1318-7103 lines (links between species interactions). ②The fish community was characterized with the intensive interactions, high degrees of aggregation (C ranged between 0.84 and 0.98), high energy transfer efficiencies (A ranged between 0.02 and 0.09), with a weakening tendency of species interactions (Co ranged between 0.32 and 0.48) from 2016 to 2018. The fish community of Leizhou Bay waters was kept in a state of stability in all. ③At the local small scale (20°40'-21°00'N, 110°30'-110°45'E), traits of species interactions of the fish community were similar on the seasonal and annual scale. Two traits were the important internal factors driving the coexistence of multiple fish species in the Leizhou Bay waters. The first was the degree of directly interspecific associations which was positively correlated with the intensity of species interactions (P<0.01). And the second was the degree of local aggregation which was negatively correlated with both the degree of directly interspecific associations and the intensity of species interactions (P<0.01). This study provides clues for the quantitative analysis on the stability of fish community structure and planning of effective coastal fishery resources management and conservation.