Malignant melanoma is a common cancer of skin. Its incidence is growing rapidly in recent years,1 however, there is no effective therapy for this cancer. Retinoids are metabolites or derivatives of vitamin A. They are essential for growth, differentiation, and maintenance of epithelial tissues.2 Previous studies showed that retinoids could inhibit growth of many kinds of malignant tumor cell lines and induce its apoptosis,3,4 including malignant melanoma cell lines.5 Some retinoids have therapeutic action to malignant melanoma, such as all-trans retinoic acid (ATRA) and 13-cis-RA.6,7 Retinoids take effects mainly through two kinds of nuclear receptors, retinoic acid receptor (RAR) and retinoic acid X receptor (RXR). In this study, we have investigated the effects of diverse retinoids and receptor agonists in inhibiting proliferation and inducing apoptosis of human melanoma cell line A375.