Abstract: Objective: To study the apoptosis-inducing effects of curcumin(CUR) combined with paclitaxel(PA) on lung cancer cell line PC9.Methods: The PC9 cells were treated with different concentrations of single drug or two drugs combination.The anti-proliferative effect of drug was measured using MTT.The effects of single drug and two drugs combination on the cell cycle distribution and apoptosis were measured by flow cytometry.The expressions of apoptosis-related protein were detected by western blotting.Results: Two drugs could inhibit the prolification of PC9 cells with time-and concentration-dependent manner,and the profilication inhibiting rate of curcumin combined with paclitaxel was higher than that of CUR or PA.The apoptosis and G₀/G₁ phase arrest of PC9 cells treated with drug combination significantly enhanced(P<0.01).The protein expression changes of Caspase-3,Bcl-2 and Bax in PC9 cells teated with drug combination were significantly more than that with single drug(P<0.01).Conclusions: The CUR and PA can inhibit the proliferation of human lung cancer cell PC9,induce apoptosis,block cell G₀/G₁ phase and inprove the Caspase-3 activity.Two drugs combination can significnatly promote the PC9 cells apoptosis.