Tumor cells have different physiological and biochemical features as compared to normal cells; abnormal expressi of certain genes is also found in tumor cells. Overexpression of genes provide targets for targetedadministration of drugs, which can avoid damage to normal cells during treatment of tumors. Fatty acid synthase (FAS) and human epidermal growth factor receptor2 (HER2) are both overexpressed in some tumor cells. Herceptin, an HER2targeted agent, has been used to treat HER2positive breast cancer patients worldwide and has obtained satisfactory outcome. Cerulomycin, an agenttargeting FAS, is now in FDA clinical trial. Recent researches have shown that FAS and HER2 are simultaneously overexpressed in some tumors, such as breast cancer cells and ovarian cancer cells; and there is a connection between their signal pathways and a synergistic effect between them. This paper reviews the relationship between FAS and HER2 in tumor cells.