The feeding ecology of fish is an important part of the study of the marine ecosystem. Through predation, fish not only satisfy their own growth and development but also promote energy flow in the ecosystem. Studies on the feeding habits and trophic interactions of fish can provide a scientific basis for ecosystem-based fishery management. Pennahia argentata and Atrobucca nibe are two common economic fish species in China and belong to the Sciaenidae family. Many studies have been done on these two species, except for the feeding relationship between them. To analyze the feeding habits and trophic interactions between these two species, biological samples for both species were collected based on bottom trawl surveys conducted in the southern coastal waters of Zhejiang in August and November 2020 and January 2021. A total of 287 stomach samples of P. argentata and 204 stomach samples of A. nibe were collected to perform stomach content analyses. The percentage index of relative importance (IRI%) was used to measure the importance of each prey item. Cluster analysis was used to evaluate the ontogenetic variation in their feeding habits. To facilitate the analysis of the relationship between feeding habits and size classes, the samples of P. argentata were divided into eight size classes, and samples of A. nibe were divided into six size classes. The overlap coefficient of diet was used to estimate the overlap of food composition between these two species. The results indicated that the prey items of P. argentata included 48 species, among which, Copepoda was the main prey category and Calanus sp. (IRI%=53.73%) was the dominant prey species. A. nibe fed on 43 species, mainly fish and shrimp, with Benthosema pterotum (IRI%= 65.25%) being the dominant prey species. By feeding on different proportions of prey, these two species ease the feeding competition by having different main prey categories. Furthermore, obvious ontogenetic variations in the feeding habits were observed for both species. With the increase of predator body length, the main prey items switched from small-sized items to large-sized items, and their feeding intensity changed correspondingly. The feeding intensity of P. argentata gradually decreased with body length, while the feeding intensity of A. nibe decreased at first and then increased with body length. Trophic niche breadth indicated the place of a predator in the ecosystem in relation to its prey. The trophic niche breadth of A. nibe (3.06) was much wider than that of P. argentata (1.82), indicating that A. nibe had a better ability and range of utilizing food resources. The overall feeding overlap value between these two species was 0.22, whereas high overlap values occurred in certain body length group combinations. For example, majority of the feeding overlap values between all body length groups of A. nibe and of P. argentata groups with body length in range of 120–159 mm were higher than 0.6, indicating significant feeding overlap. This phenomenon revealed the possibility of feeding competition between P. argentata and A. nibe in the southern coastal waters of Zhejiang. The findings of this study enhanced our understanding of the trophic interaction between P. argentata and A. nibe and provided basic data for ecosystem-based fishery management in the southern coastal waters of Zhejiang.