Objectives : The aim of this study was to evaluate the anti-depressant effect of Chilbokum on rats under the forced swimming test (FST) Methods : The rats were treated with the herbal extract, Chilbokum. In order to induce depression-like symptoms, the FST was conducted afterwards. The immobility time was measured during a 5-min experimental session. The alterations of the 5-HT level in the hypothalamus and hippocampus and the change of corticosterone level in the blood induced by FST were determined in the rats. Results : The results were as follows: 1. The immobility time during 5 min of FST in the drug administration group showed significant decreases compared with the control group (p<0.05). 2. The FST+Chilbokum group had significantly increased 5-HT levels of the hypothalamus and hippocampus, compared with the control group (p<0.05, respectively). 3. The FST+Chilbokum group had significantly decreased corticosterone levels, compared with the control group (p<0.05). Conclusions : These results demonstrate that the reduced immobility time by Chilbokum may be mediated by the increase in 5-HT level in the hypothalamus and hippocampus, suggesting that Chilbokum has a potential therapeutic efficacy for human depression.