The pharmacokinetics of quinocetone and its major metabolites in healthy swine was investigated in this paper.Quinocetone was administered to 8 healthy cross-bread swine intravenously and orally at a dosage of 4 and 40 mg kg-1body weight respectively in a randomized crossover design test with two-week washout period. A sensitive highperformanceliquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for thedetermination of quinocetone and its metabolite 1-desoxyquinocetone in plasma. Plasma concentration versus timeprofiles of quinocetone and its metabolite 1-desoxyquinocetone were analyzed by non-compartmental analysis usingWinnonlin 5.2 software. Mean maximum concentrations (Cmax) for quinocetone was found to be (0.56±0.13) μg mL-1 at 2.92 h,after oral administration of quinocetone. Mean maximum concentrations (Cmax) for 1-desoxyquinocetone after intravenousor oral administration of quinocetone were (0.0095±0.0012) μg mL-1 at 0.083 h and (0.0067±0.0053) μg mL-1 at 3.08 h. Theapparent elimination half-lives (T1/2) for quinocetone and its metabolite 1-desoxyquinocetone were (2.24±0.24) and(5.23±0.56) h after intravenous administration of quinocetone and (2.91±0.29) and (11.85±2.89) h after oral administrationof quinocetone, respectively. Mean areas under the plasma concentration-time curve (AUC0- ) for quinocetone and 1-desoxyquinocetone were (2.02±0.15) and (0.2±0.002) μg h mL-1 respectively after intravenous administration of quinocetone,and (3.5±0.79) and (0.053±0.03) μg h mL-1 after oral administration of quinocetone, respectively. Quinocetone was rapidlyabsorbed and metabolized in swine after oral and intravenous administration. The plasma concentration-time curve(AUC0- ) of 1-desoxyquinocetone were much smaller than those of quinocetone, while the elimination half-lives (T1/2) weremuch longer than those of quinocetone after intravenously (i.v.) or oral administration.