Abstract: Objective To evaluate the apoptosis-inducing effect of flavone(which was extracted from Yunnan purpleblow maple) on YTMLC (Yunnan Gejiu Lung Squamous Carcinoma Cells) cell line and related altered gene expression change, this study would provide experimental basis for the clinical use of lung cancer theraphy. Methods MTT(Methy triazolyl tetrazolium) assay was used to evaluate the growth inhibiting effects of the flavone on YTMLC cells. Flow cytometry TUNEL assay was applied to detect the apoptosis rate of YTMLC cells after incubation with the flavone. Apoptosis related gene expression of YTMLC cells was tested by reverse transcriptive polymerase chain reaction(RT-PCR). Results The flavone exhibited a growth inhibitory effect on YTMLC cells, with 50% inhibition concentration(IC50) value (108.53±8.22) mg/L, after incubated for 48 h. Flow cytometry showed that the flavone of Yunnan purpleblow maple induced both apoptosis and necrosis. While upregulating the expression of p53、p21、Bax and Caspase-3, the flavone also downregulated the expression level of Bcl-2. Conclusion The flavone of Yunnan purpleblow maple can inhibit the growth of lung cancer cell (YTMLC) in vitro, and leads to apoptosis and necrosis of the tumor cells. The expression levels of apoptosis-related genes were altered, which implies its mechanism.