Melinjo has been used for making “emping”, flour, and as vegetables, however skin melinjo has not been used optimally. The purpose of this experiment was to determine antioxidant activity from red skin melinjo using solvent combination of ethanol and ethyl acetate (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100), combination of extraction time (3, 6, and 9 hours), and combination of extraction temperature (30°C, 40°C, and 50°C). The best time and temperature for extraction were determined using RSM (Response Surface Methodology). Antioxidant activity was determined by IC50, fenolic in total, content of vitamin C, color spectrum, and chromatography. The result obtained showed that solvent combination of ehanol and ethyl acetate by ratio 20 : 80 has the highest fenolic in total (11.805 mg GAE/g extract), low IC50 (1723.231 ppm) with maximum wavelength 475.17 nm. The component responsible for antioxidant activity was considered as carotene. Light and pH will decrease antioxidant activity. Combination of pH being used in this experiment were pH 4, 5, 6, 7, and 8 with combination of neon lamp, pijar lamp, and LED lamp. The lowest decline of antioxidant activity was in extract with pH 5 and LED lamp. Red skin melinjo consist of beta karoten (537.35 ppm), stigmast-5-en-3-ol, gamma tocopherol, and beta tocopherol as antioxidant.