Abstract: Objective To investigate the effect of melittin on proliferation， apoptosis and PI3K／Akt signal pathway in non-small cell lung cancer（NSCLC）. Methods The NSCLC cell lines A549， SPC-A1 and human lung epithelial cell line 16HBE were treated with different doses of melittin（0， 10， 20， 50， 100 μmol／L）. The Methyl thiazolyl tetrazolium（MTT） was used to determine the changes of proliferation inhibition rate at 24， 48， 72 and 96 h after the treatment of melittin. Meanwhile， the Annexin-FITC／PI double staining method and PI single staining method were used to measure the apoptotic rates and cell cycle via flow cytometry. Western blotting was used to detect the protein levels of Akt，PTEN and caspase-9 at 48 h after treatment with different concentrations of melittin. Results Melittin elevated the proliferation inhibition rates in a dose-and time-dependent manner on A549 and SPC-A1 cells（P＜0.05） without cytotoxic effect on 16HBE（P＞0.05）. In addition to similar proportion of G2／M phase and late apoptotic rate at 24 h of 10 μmol／L， there were increased early and late apoptosis rates， cell percentage of G0／G1 phase and protein levels of PTEN and caspase-9 but decreased cell percentage of S and G2／M phases and Akt level in 10-100 μmol／L melittin versus 0 μmol／L melittin with statistical significant differences（P＜0.05）. Significant difference was observed on the above indices during the concentration of 10-100 μmol／L（P＜0.05）. Conclusion Melittin have toxic effects on the NSCLC cells， but have no effect on normal cells. It can induce the apoptosis and cell cycle arrest of A549 cell with the effects of inhibiting the PI3K／Akt signaling pathway.