To evaluate the effect of Choakwiyeum water extract on the male reproductive functions, experiments were performed on male rats. The results obtained were as follows: 1. Intromission frequency was increased significantly after the administration of Choakwiyeum water extract in male rats. 2. Intromission latency was increased significantly after the administration of Choakwiyeum water extract and ketoconazole in male rats. 3. Mount frequency was increased significantly after the administration of Cboakwiyeum water extract and TCDD in male rats. 4. Serum testosterone concentration was increased significantly after the administration of Choakwiyeum water extract in male rats. 5. Serum testosterone concentration was increased significantly after the administration of Choakwiyeum water extract and ketoconazole in male rats.