OBJECTIVE To establish t he method for determining the concentrations of fluoxetine ，norfluoxetine and sertraline in human placental perfusate method and their placental permeability. METHODS Using glyburide as internal standard ，the samples were pretreated by protein precipitation method and detected by ultra-fast liquid chromatograph-mass spectrometer/mass spectrometer （UFLC-MS/MS）. The determination was performed on Synergi TM Hydro-RP 80A LC column with mobile phase consisted of water （containing 0.1％ formic acid ）-acetonitrile（containing 0.1％ formic acid ）at the flow rate of 0.70 mL/min，with a gradient elution. The column temperature was set at 40 ℃，and sample size was 5 μL. Detection was performed with electrospray ionization source in multipl e reaction monitoring mode . The ion pairs for quantitative analysis we re m/z 309.9→148.1（fluoxetine），m/z 296.0→134.4 （-167）， （norfluoxetine），m/z 306.1→159.0 （sertraline），m/z 493.9→ No.2018FE001（-207），（internal standard ）. The perfusion model of singal placenta under bidrectional cardiopulmonary bypass was established. Fluoxetine （160 ng/mL），norfluoxetine（160 ng/mL）， sertraline（100 ng/mL）and antipyrine （positive control ，ng/mL）were added into the maternal perfusate. The concen- 65324888 trations of fluoxe tine， norfluoxetine and sertrali ne were measured by above UFLC-MS/MS at 0，10，20，30，45，60，90，120，150 and 180 min of circulation ，and the placental permeability was calculated. RESULTS The linear range of fluoxetine ，norfluoxetine and sertraline were 5.00-500 ng/mL（all r＞ 0.990），and the lower limits of quantification were all 5.00 ng/mL. The RSDs of intra-day and inter-day were all less than 14.0％， and relative error ranged －9.6％ to 14.7％. The relative error of stability test was －4.0％ to 11.0％；the residual effect ，extraction method and matrix effect did not affect the quantitative analysis of the substance to be tested. Totally 31 perfusion model of human placenta under cardiopulmonary bypass were successfully established ，including 15 fluoxetine and norfluoxetine perfusion ，10 sertraline perfusion and 6 antipyrine perfusion. After 3 hours of perfusion ，the average placental permeability of fluoxetine ， norfluoxetine and sertraline were （8.74 ± 1.67）％ ，（10.70 ± 4.81）％ ，（5.90 ± 1.25）％ ，respectively. CONCLUSIONS The established UPLC-MS/MS is simple ，sensitive and accurate. It can be used for determination of fluoxetine ，norfluoxetine and sertraline in human placental perfusate. Fluoxetine ，norfluoxetine and sertraline can pass through the placenta ，but sertraline has a lower placental permeability.