Abstract: The pharmacokinetics of sulfamethazine (SM2), sulfamethoxydiazine(SMD) and sulfadiazine(SD) in gill, hepatopancreas and muscle of Fenneropenaeus chinensis were investigated following oral administration (100 mg/kg) at (24.6±2.4) ℃. The results showed that for SM2, the values of T1/2β in gill, hepatopancreas and muscle were 23.067, 34.162 and 16.559 h, respectively. For SD, T1/2β in gill, hepatopancreas and muscle were 29.157, 34.272 and 27.929 h, respectively. For SMD, T1/2β in gill, hepatopancreas and muscle were 47.657, 55.271 and 32.237 h, respectively. The rate of different pharmic elimination in the same tissue was in the following order: SM2>SD>SMD. The rate of pharmic elimination in different tissues for taking orally the same drug was in the following order: muscle > gill > hepatopancreas. For SM2, CL in gill, hepatopancreas and muscle were 0.673, 0.171 and 0.464 L/(h·kg), respectively. For SD, CL in gill, hepatopancreas and muscle were 0.496, 0.214 and 0.463 L/(h·kg), respectively. For SMD, CL in gill, hepatopancreas and muscle were 0.29, 0.082 and 0.362 L/(h·kg), respectively. Therefore, the slowest clearance rate in the same tissue was SD. For the same pharmacokinetics, the fastest clearance rate was in the gill. For SM2, AUC(0—72) in gill, hepatopancreas and muscle were 138.476, 493.02 and 206.572 mg/(L·h), respectively. For SD, AUC(0—72) in gill, hepatopancreas and muscle were 147.919, 379.039 and 186. 495 mg/(L·h), respectively. For SMD, AUC(0—72) in gill, hepatopancreas and muscle were 218.024, 629.311 and 229.819 mg/(L·h), respectively. The AUC of hepatopancreas was higher than other tissues for taking orally the same drug, and the AUC of SMD was larger than others in the same tissue. The results illustrated the metabolism of the three sulfa drugs in gill, hepatopancreas and muscle of F. chinensis, and indicated that hepatopancreas was the main tissue of F. chinensis for sulfa drugs residue within 72 h.This study provides reference for more scientific and reasonable use of sulfa drugs in the breeding process of Fenneropenaeus chinensis.[Chinese Fishery Quality and Standards, 2014, 4(4):56-62]