The purpose of this study is to examine the antioxidant activity in the germ cells of the extract of Psoraleae fructus. The extract was studied for dipheny-picryl-hydrazyl (DPPH) radical scavenging activity, GC-1 cell viability by a modified MTT assay, the effects on $H_2O_2$-induced cytotoxicity by MTT assay and lipid perixidation by malondialdehyde (MDA) formation, respectively. The results showed that the extract scavenged DPPH radical with the IC50 being 0.427 mg/mL. The extract was dose-dependent in growth of GC-1 cell. $H_2O_2$-induced cytotoxicity (67.7 %) was blocked by the extract concentration- dependently. Furthermore, the extract also displayed a dose-dependent reduction of MDA formation on $H_2O_2$-induced lipid peroxidation. In conclusion, the extract of Psoraleae fructus has potent antioxidant activity.