To investigate the inhibitive effect and the underlying mechanism of Xiaoji Decoction (ae c -eyen (R), XJD) in human lung cancer A549 cells. A549 cells in logarithmic proliferation were cultivated in RPMI-1640 containing 10% low, medium or high dosages of XJD serum. The inhibitive effect of XJD in A549 cell proliferation was assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. The pro-apoptotic effect of XJD in A549 cells was observed by fluorescence microscope via Hoechst 33258 staining. The role of the Akt signaling pathway was observed by examining the presence of p-Akt protein by Western blot and the mRNA expression of downstream proteins such as Bcl-2/Bcl-XL-associated death promoter (BAD) and caspase-9 by real time polymerase chain reaction. MTT assay revealed that XJD could inhibit A549 proliferation in a dose- and time-dependent manner. Hoechst 33258 staining showed that XJD induced the typical nuclear apoptotic morphology after XJD treatment. Moreover, XJD could reduce the phosphorylation of Akt and increase the mRNA expression of BAD and caspase-9. XJD can inhibit the proliferation of A549 cells in a dose- and time-dependent manner through signaling Akt pathway via up-regulating the expression of BAD and caspase-9. XJD may provide a novel therapeutic model for lung cancer and deserve further study.