Abstract: The fermented soybean meal (FSM) was used as a replacement of fish meal (FM) in a practical diet with 45% protein and 10% lipid, to investigate its effects on the growth, intestinal histology, and the structure of intestinal dominant bacteria in juvenile large yellow croaker. FM was replaced by 0, 15%, 30%, 45%, 60% and 75% of FSM (FSM0, FSM15, FSM30, FSM45, FSM60 and FSM75), respectively. The fish of 10.49 ± 0.03 g was hand-fed daily to satiation twice for 56 days. Results showed that survival was not significantly affected with all the diets (P>0.05), but in groups FSM60 and FSM75, theSR had a downward trend. In comparison with FM0, the weight gain rate (WGR) and specific growth rate (SGR) in FSM60 and FSM75 groups decreased significantly (P<0.05), while the feed conversion rate (FCR) increased significantly (P<0.05). Feed intake (FI) increased significantly in FSM60 and FSM75 groups (P<0.05), compared with that in FSM0, FSM15, FSM30 and FSM45 groups. The observed intestinal histology results showed that Mucosa thickness, Mucosafold height, Laminapropria width and Gobletcell quantity were not significantly affected in all the diets (P>0.05). Sequencing results of intestinal contents from Illumina-MiSeq high-throughput sequencing technology showed that the index of Chao1, Shannon, Simpson and Good coverage in FSM0 (TC the control), FSM45 (TB the best group in growth) and FSM75 (TW the worst group in growth) were not significantly affected (P>0.05).Firmicutes group totally dominated the bacterial communities in juvenile large yellow croaker. Paenibacillus genus was the most dominant bacteria in microbial ecosystem. Bacterial composition had certain effect on the growth of large yellow croaker: compared with TW group, the species richness of Paenibacillus and Alkaliphilus increased significantly in TB group and TC group (P<0.05). However, compared with TW group, the species richness ofEnhydrobacter in TB and Paracoccus in TC decreased significantly (P<0.05). These results suggested that the optimal dietary protein level was about 45% without negtive effects on the growth, intestinal histology, and the structure of intestinal dominant bacteria in juvenile large yellow croaker.