Abstract: This experiment was conducted to study the elimination of Thiamphenicol (TAP) residue in common carp (cyprinus carpio) and crucian carp (carassius auratus), preparing for the determination of the withdrawal time. After oral administration of TAP with a dosage of 30 mg/kg body weight per day for 3 days, the fish was sampled at certain time. Quantitative analysis was performed with external standard method and TAP concentrations in tissues were analyzed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that the linear relationship of TAP was nice (r2=0.9987) in 0.1 ng/mL to 200 ng/mL concentration range and the recovery ranged from 81.33% to 109.72%. The detection indicated that the residues of TAP in common carp and crucian carp had a down trend. At the 25th day, the residue started to below the maximum residue limits (MRLs) of China and EU. It was proposed that the withdrawal time should be 25 days after administration.