Black soybean seed coat were extracted using three solvent systems: 70% acetone, ethanol and methanol. The extracts were tested for their total phenolic content, total flavonoid content and antioxidant activities. The results showed that the extracts with acetone as the extraction agent had the highest yield［(11.23±0.005) g/100 g］, and the extracts had the highest total phenol content of (845.32±21.35) mg/g and total flavonoids content of (63.72±2.35) mg/g. Meanwhile, IC₅₀ of acetone extract on DPPH free radical and ABTS free radical were (0.059±0.005) mg/mL and (0.057±0.004) mg/mL, respectively. The antioxidant activities were lower than ascorbic acid but higher than methanol extracts and ethanol extracts.