Cordyceps militaris (CM) has been used as a traditional folk medicine to strengthen the immune system and regain energy in Far East Asian countries. Some of men have been suffered from the insufficient secretion of testosterone causing by physical factors, social and psychological factors. Testosterone is an essential steroid hormone controlling male reproductive function. Alternative medicines in plants, fungi, and insects have been studied to enhance sexuality. Cordyceps species including Cordyceps sinensis and C. militaris has been used as for the enhancement of sexual function for hundreds of years. In the present study, we determined the effect of fruiting bodies of C. militaris which cultured on bee drone medium (DCM) on testosterone concentration in Sprague-Dawley rats. Eighteen rats per group were housed to regular diet or diet supplemented with DCM for 4 weeks. Serum was collected from 6 rats per group. Results showed that changes of the body weight, food and water intake of the rats were not observed in this study. However, DCM significantly stimulated testosterone production (p < 0.05) compared to the control. Hence, it suggests that fruiting bodies of C. militaris grown on the bee drone medium might be developed as a complementary medicine to improve sexual hormones.