Objective To investigate the effects of gambogenic acid(GNA) on the proliferation and apoptosis of A549 lung canc‐er cells and its possible mechanism of regulation .Methods A549 cells were treated with different concentrations of GNA ,which di‐vided into control group and GNA group(0 .5 ,1 .5 ,20 mg/L) .The cell proliferation and apoptosis of A549 was analyzed by MTT , Hoechst staining ;The expression of apoptosis‐related protein caspase3 ,caspase9 ,p53 and NF‐κB were studied by Western blot .Re‐sults GNA could inhibit growth of A549 cells ;Moreover GNA could also induce apoptosis with the concentration increased more obviously ;Western blot showed that GNA down‐regulate NF‐κB ,increased caspase3 ,caspase9 and p53 expression(P<0 .05) .Con‐clusion GNA can efficiently promote the cell proliferation inhibition and the apoptosis of A 549 cells .