The lung cancer is one of the most dangerous cancers and is also the leading cause of cancer death worldwide, accounting for about 1.3 million deaths annually. However in clinical practice, lung cancer therapies commonly do with chemotherapy, although it is hard because the lung cancer may progress to metastasis stage. The metastasis of lung cancer is highly dependent of expression of matrix metalloproteinase, and correlated with phosphorylation of ERK1/2 and PI3K/Akt pathways. Therefore agents’ down expressed matrix metalloproteinase or suppressed phosphorylation of ERK1/2 and PI3K/Akt pathways could inhibit the metastasis stage. In this study we aimed to investigate the effects of genistein, an isoflavonoid, on A-549 cell line. Lactate dehydrogenase (LDH) release, Microculture tetrazolium test (MTT assay), real-time PCR and zymography were used to evaluate the effects of genistein on cell cytotoxicity, cell proliferation, expression of mRNA and protein of MMP-2 in lung cancer A549 cell line. The results indicated that genistein, in a dose-dependent manner, without applying any cytotoxic effect, inhibited cell proliferation and downregulated MMP-2 mRNA and protein expression in A549 cell line. In addition, results of inhibition of ERK1/2 and PI3K/Akt pathways phosphorylation by ELISA indicated that genistein inhibited phosphorylation rate of both pathways. Therefore it seems that genistein can decrease recurrence and decreased the migration and invasion of human non-small cell lung cancer cells (A549 cell line) by an efficient antimetastatic effect. This issue should be further examined for the clinical treatment.