Abstract: Investigation was conducted on bacterial contamination and antimicrobial resistance of the strains isolated from the gills of commercial Grass carp (Ctenopharyngodon idellus ) in Xuzhou, four isolated strains were gram-negative and short rod-shaped bacteria, and tentatively named ZYF-1, ZYF-2, ZYF-3 and ZYF- 4, respectively. According to the values of coding method of four strains, ZYF-1 was identified as Shigella sp., ZYF-2 and ZYF-3 were identified as Escherichia coli, and ZYF-4 was identified as Serratia fonticola. The antimicrobial susceptibility assay indicated that the resistance rates of ZYF-1, ZYF-2, ZYF-3 and ZYF-4 strains were 75.8%、72.4%、65.5% and 82.8%, respectively. Four strains showed antibiotic resistance to eleven kinds of antibiotics, such as ampicillin, amoxicillin, trimethoprim- sulfamethoxazole, sulfisoxazole, trimethoprim and so on. It is concluded that there are Shigella and Escherichia coli contamination in commercially availableCtenopharyngodon idellus in Xuzhou, and the bacteria showed multi-drug resistances in antimicrobial susceptibility assay. The conclusion will provide scientific references for identification of foodborne bacteria and control of bacterial disease in fish.