Considering the influence of ethanol concentration, extraction time, extraction temperature and liquid-to-material ratio on the extraction rate, the experiments were proposed for procyanidins extraction, which was from small black bean coats in Northern Shaanxi, by single factor method and response surface methodology. The experiments were designed by the Box-Behnken of response surface software. The mathematical model of the extraction process and the regression equation of the model were established through experimental data. The optimum conditions of the extraction process were calculated by the mathematical model, and the antioxidant anctivity of procyanidins was also studied . The results showed that the optimum extraction conditions of the procyanidins from small black bean coats were as follows: extraction time 4.2 h, extraction temperature 53 ℃, the liquid to material ratio 221 (mL/g) and ethanol concentration 60%. Under the optimized condition, the average extraction rate was 5.38%. The antioxidant activity study showed that abilities of procyanidins in black bean coasts to scavenge DPPH and hydroxyl radical and superoxide anion were good, and the IC₅₀ were 0.075, 0.590, 0.220 mg/mL respectively.