Abstract: The formation and metastasis of tumor cells are closely related to the gene regulation. It is critical to elucidate the molecular mechanism of a compound using in cancer therapy. In this article, we reviewed the anti-cancer molecular mechanism of arsenic trioxide and artemisinin. Its anti-cancer function mainly includes:regulation of ① cell cycle regulatory proteins to inhibit tumor cell proliferation, ② cell apoptosis signal transduction pathway to promote apoptosis in tumor cells, ③ immortalization associated genes to reduce the life of tumor cells, ④ angiogenesis/invasion/metastasis gene to block the spread of tumor cells, ⑤ promoter methylation and protein ubiquitination gene to enhance anti-oncogene expression and ubiquitin-mediated protein degradation, ⑥ microRNA to inhibit proliferation or induce apoptosis in tumor cells, ⑦ DNA synthesis and repair of DNA damage and repair gene to decrease the DNA synthesis of tumor cells, ⑧ signal transduction pathways of cell proliferation/apoptosis and invasion/metastasis etc., ⑨ the expression of hor-mone receptors and so on. We indicated the problems existing in current studies and also prospected the future of using the compound to fight cancer.