Objective To study the growth effect of human cholangiocarcinoma cell line QBC939 treated by norcantharidin (NCTD) and preliminary illustrate the potential mechanism.Methods The human cholangiocarcinoma cell line QBC939 was detected by MTT assay,flow cytometry,immunocytochemistry after the treatment of NCTD in vitro.Results NCTD displayed inhibitory effect on growth of QBC939 from different doses of 0.125,0.75,2.5,10,120 μg/ml after 48 h (P ＜0.05).It was in a dose and time dependent manner.Dose-effect curve was drawn and IC50 value was (3.66±1.14) μg/ml.The flow cytometric profiles showed that the rate of cell apoptosis enhanced following increasing the concentration of NCTD[(8.6±0.4) ％,(17.6±0.3) ％,(22.9±0.4) ％,(25.5±0.9) ％ and (31.1±1.5) ％,respectively]and cells blocked in the G2/M phase after treatment with 2.5 μg/ml NCTD[(14.1±1.0) ％ and (5.7±0.3) ％].The expression of the protein caspase-3 elevated after different concentrations of NCTD co-cultured with QBC939 compare with contrast group.Conclusion NCTD has an inhibitory effect on proliferation of QBC939 cell line,and the mechanism might be related to the induction of cell apoptosis and blockade of cell cycle.