To evaluate effect of Gamimajeonojahwan(GMOH) water extract on sexual functions, we orally administered GMOH exract(1,100㎎/㎏) for four weeks in male rats impaired by 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) and ketoconazole(KZ). And we investigated the sexual behaviors such as mount latency, mount frequency, intromission latency, intromission frequency, ejaculation period and ejaculation latency. Serum testosterone concentrations also are evaluated in GMOH-and/or vehicle-treated male rats. The results were obtained as follows: GMOH inhibited the increase of intromission latency by TCDD in male rats. GMOH inhibited the decrease of intromission frequency by TCDD in male rats. GMOH inhibited the increase of ejaculation latency by TCDD in male rats. GMOH inhibited the decrease of serum testosterone concentration by TCDD in male rats. GMOH inhibited the decrease of serum testosterone concentration by KZ in male rats. These results suggest that GMOH water extract is active in improving sexual functions and protecting a decrease of testosterone concentrations induced by TCDD and KZ in male rats.