Purpose : This study was conducted to investigate the dose dependent effects of Panax Ginseng on the reproductive functions in mice. Methods : We used the 8-week-old mice, and administered 0.2ml extract solution of Panax Ginseng in the different concentration once a day for 60 days. The control group was administered 0.2ml normal saline in the same way and duration. We counted the total, motile and normal sperm number of the cauda epididymis and measured the activities of sperm hyaluronidase, peroxidase and catalase of the isolated testis tissues. And we observed histological changes of surgically isolated testis by histochemical methods. Results : All Panax Ginseng extract solution groups showed significantly dose dependent differences in the total number, the motility and normality of sperms compared with the control group, respectively. In the histological analysis of the testicular tissues, all Panax Ginseng extract solution groups showed the enlargement of testicular lobe diameter and apparent angiogenesis between seminiferous tubules. And the activity of typical sperm enzyme, hyaluronidase, was significantly increased in the Panax Ginseng extract solution groups compared to the control group. In the antioxidant activity analysis, the activities of peroxidase and catalase were significantly increased in the Panax Ginseng extract solution groups compared to the control group. Conclusion : This study shows that Panax Giseng has the beneficial effects on the concentration, morphology and motility of sperm, the activities of sperm hyaluronidase, testicular peroxidase and catalase. We can suggest that Panax Ginseng be useful for the treatment of male infertility.