Abstract:Proanthocyanidins can prevent the formation of free radicals and also can eliminate them. It has an important economic value to extract the abundant proanthocyanidins from purple eggplant peel. Also， the effectthat extraction time，ethanol concentration and solid-liquid ratio had on the extraction rate of proanthocyanidins was investigated. Then，the response surface of solid-liquid ratio，extraction time，ethanol concentration in extraction process was designed through using the central composite. It reached a conclusion that the optimum ex原 traction conditions of proanthocyanidins inside purple eggplant peel were as following：the solid-liquid ratio was 1：15（g/mL），extraction time was 4 h，and ethanol concentration was 80 %. In such case，the highest extraction rate was 10.46 %.