The pharmacokinetics of florfenicol (FF) after intramuscular injection was investigated in the Chinese Mitten-handed Crab (Eriocheir sinensis) at 17℃ . Hemolymph,muscle and liver samples were obtained and analyzed by a high-performance liquid chromatography with fluorescence detection method, and the corresponding pharmacokinetic parameters were calculated with the 3P97 software. The florfenicol level in hemolymph and muscle reached maximum momentarily,while that in liver reached a maximum then declined at three administration doses (5. 0,10. 0,20. 0 mg /kg). The kinetic profile of florfenicol in hemolymph,muscle and liver was conformed to a two-compartment model. The important parameters were listed. When three doses were injected,the absorption half-lives (T_1/2α) and the elimination half-lives (T_1/2β) in hemolymph were 0. 04,0. 21,0. 87 and 0. 60,1. 48,3. 29 h,respectively,and the total body clearance (CLs) were 2. 17, 1. 99 and 2. 12 ml /(kg·h),respectively; the T_1/2α and T_1/2β in muscle were 1. 38,0. 93,0. 47 h and 10. 39, 31. 78,23. 91 h,respectively,and the CLs were 0. 07,0. 03 and 0. 03 ml /(kg·h),respectively; the T_1/2α and T_1/2β in liver were 0. 69,0. 07,0. 12 h and 0. 73,4. 90,4. 49 h,respectively,and the CLs were 1. 79, 2. 55,and 3. 89 ml /(kg·h),respectively.