Objective: These studies were undertaken to evaluate the effects of the different administration duration of Morindae Radix extract solution on spermatogenic abilities such as concentration, motility and morphological normality of sperm from the testes and the activities of sperm hyaluronidase. Materials and Method: We used 8-week-old ICR mice and administered 0.3mg/g extract solution of Morindae Radix once a day for 30, 60, 90 and 120 days. The control group was administered normal saline in the same way and duration. We examined the number of total, motile and normal sperm from the cauda epididymis. We also compared the testicular tissue, especially seminiferous tubules, between the control and treated groups by histochemical methods. Finally, we observed the difference of sperm hyaluronidase activities between the control and treated groups. Results: Significant administration duration-dependent differences were observed in the concentration of total sperm, motility and normality of spermatozoa of the Morindae Radix extract solution administered groups compared to the control group. In the histological analysis of the testicular tissues, the enlargement of testicular lobe diameter and apparent vasculogenesis between testicular lobes were observed in the Morindae Radix extract solution administered groups compared to the control group. Also, the activity of hyaluronidase was significantly increased in the Morindae Radix extract solution administered groups compared to the control group. Conclusions: This study shows that the beneficial effect of Morindae Radix extract solution on the concentration, motility and morphology of sperm, the testicular tissues and the activities of sperm hyaluronidase increased the greater the duration the mice were administered it. We suggest that Morindae Radix may be useful for the treatment of male sexual dysfunction and infertility.