Objective To investigate the anti-proliferation mechanisms of Phenethyl isothiocyanate (PEITC)in human lung cancer cells line NCI-H446. Methods Human lung cancer cell line NCI-H446 was cultured in vitro,and treated with 10,30,50μmol/L PEITC for 24 h respectively. Cell viability and apoptosis were analyzed by methylthiazolyldiphenyl-tetrazolium bromide (MTT)assay and flow cytometry,respectively. Phosphorylation of Akt,activation of caspase-3 and caspase-9 in NCI-H446 cells,and production of cytochrome C in cytoplasm were detected by Western blot. Expression of phosphatase and tensin homologue (PTEN)was detected by real-time PCR. Results PEITC significantly reduced NCI-H446 cells proliferation in dose-dependent manner (P<0.05 ),and apoptosis was also inducted after PEITC administration. PEITC also markedly induced expression of caspase-3 and caspase-9,as compared with control group. And the level of cytochrome C in the cytoplasm was also increased after treatment with PEITC.Furthermore,PEITC treatment significantly increased the mRNA level of PTEN in NCI-H446 cells. Conclusion PEITC may be used as a potential anti-lung cancer agent by regulationg PI3K/AKT pathway and increasing PETN expression.