The resistance of bacteria to 12 different antibiotics was investigated in shrirnp farms on Donghai Island,China.Antibiotic-resistant bacteria were found to be widespread in shrimp farms,indicating a high environmental risk.Further,significant differences were found in bacterial strains among farms (ANOVA,p<0.05),showing resistance to antibiotics such as ampicillin,trimethoprim,compound sinomi,tetracycline,chloramphenicol and cefazolin.No significant differences in antibiotic resistance were found among 6 hatcheries evaluated in this study (ANOVA,p>0.05),between exalted and traditional shrimp ponds (ANOVA,p>0.05),and between cultural ponds and corresponding control water source sites (T-test,p>0.05).In cultural ponds,no significant difference in bacterial resistance to antibiotics was found between water and sediment (T-test,p>0.05),and antibiotic resistance of bacteria from water showed a significant positive correlation with that from sediment (p<0.05).Therefore,our study indicates that bacterial multiple antibiotic resistance (MAR) is more widespread in shrimp hatcheries than ponds.