Depression is a very difficult disease to be cured because several nervous systems are involved. In the present study, we evaluated the effects of Keum-Ryung-Ja-San (KRJS), a traditional herbal prescription, on depressive behaviors in mice using the forced swimming test. KRJS was given 1 h prior to the forced swimming test (50, 100, 200, an400 mg/kg, p.o.). The duration of immobility time in the forced swimming test was significantly reduced by KRJS treatment (200 mg/kg, P<0.05) and similar effects were observed with a classical antidepressant, imipramine (15 mg/kg, i.p.). With subchronic administrations of KRJS and its constituents at several doses for 1 week, a decreased duration of immobility time was observed with KRJS and Corydalis ternata (200 mg/kg, p.o. P<0.05). These results suggest that KRJS may have antidedpressive activities and CT may contribute to the antidepressive activity of KRJS.