This study examines a co-solvent-modified supercritical carbon dioxide (m-SC-CO2) extraction of polyphenols from rice wine lees. Chemical antioxidative activity, inhibitive melanoma tyrosinase and melanin that had been treated by the extracts were studied. Experimental results indicate that the Soxhlet 95% ethanol extract was effective in alpha,alpha-diphenyl-beta-picryl-hydrazyl (DPPH) radical scavenging (86%), ferrous ion chelating (91%), reducing ability (1.877 optical density value; OD) and tyrosinase inhibition (57%). Among the m-SC-CO2 extracts, the best antioxidative capacity was DPPH radical scavenging (31%), ferrous ion chelating (74%) and reducing ability (0.2373 CD). The amount of polyphenols in the extracts increased with the addition of ethanol in the m-SC-CO2 extraction, enhancing the antioxidative activity and tyrosinase inhibition in cells tests. The tyrosinase inhibition in an agar-plate that was treated by mSC-CO2 extract is more effective than that of Soxhlet 95% ethanol extract, indicating that the polyphenols contents in the extracts are important in the suppression of tyrosinase and melanin. (C) 2009 Elsevier B.V. All rights reserved.