Objectives To measure anti-caner activities of sesquiterpene lactones against Non small Cell Lung Cancer (NSCLC) in vitro and further investigate the effect of representative compound on NSCLC driving gene B-Raf and its related mechanism.Methods MTT assays were carried out to detect cytotoxicity of sesquiterpene lactones, including parthenolide, dehydrocostus lactone,epoxymicheliolide, micheliolide and arglabin.Scratch assay and clone formation assay were used to investigate effect on migration and proliferation.Apoptosis rates were measured by Annexin V-FITC/PI double staining.Western Blots and RT-Q-PCR were adopted to detect the expression of related proteins and mRNAs.Results All of the five sesquiterpene lactones have shown potent anti-cancer activities against NSCLC cells, of which parthenolide was the most effective compound.Parthenolide can inhibit GLC82 cells migration, colon formation and induced apoptosis in time or dose dependent manner.Furthermore, parthenolide time-dependently downregulated B-Raf expression in protein and mRNA level.Downregulation of p-MEK, p-Erk and p-STAT 3 were also observed in GLC-82 cells.At the same time, total and phosphorylated expression of GSK3 /and Akt had no changes.Conclusion Parthenolide showed strongest anti-cancer activity against NSCLC cells.It can suppress GLC-82 cells proliferation, invasion and induce apoptosis.Parthenolide took its effect by targeting on B-Raf, suppressing MAPK/Erk signaling pathway and inhibiting STATs activities, which is independent of PI3K/Akt pathway.