SS-cream (Severance Secret cream) is made up of extracts from 9 natural products for treating premature ejaculation (PE). SS-cream has been proved to be effective in the treatment of PE in pilot clinical studies. It has also been found to have a potentiating effect of their erectile capacity in some patients. Therefore, we investigated the pharmacological actions of SS-cream and the extracts of its individual components in rabbit corpus cavernosal smooth muscle to realize the effect of SS-cream on penile erection. Extracts of Bufonis Venenum induced a dose-related contraction of rabbit corpus cavernosal muscle, which was significantly inhibited by phentolamine. Extracts of Caryophylli Flos induced a dose-related relaxation in the muscle strips precontracted with phenylephrine (5 x 10^-6M; PHE). Caryophylli Flos caused a dose-dependent inhibition of the PHE induced contraction and also inhibited the contractility of Bufonis Venenum. Other extracts, when used individually or in a mixture, induced a dose-related relaxation in the precontracted muscle strips with PHE. SS-cream began to exert a relaxing effect at the concentration of 0.05 mg/ml in the muscle strips precontracted muscle strips with PHE (5 x 10^-6M); causing dose-dependent relaxation with a maximal effect at 0.2 mg/ml. The relaxation effect of SS-cream was partially inhibited by endothelial disruption and by pretreatment with methylene blue, pyrogallol, atropine, and indomethacin, although they were not statistically significant. The results show that SS-cream has a relaxing effect on cavernosal smooth muscle. And it is partly related with enhancing the NO/cyclic GMP pathway although the relaxation mechanism in detail remains to be elucidated. Therefore, SS-cream may be effective for future treatment of mild erectile dysfunction, in addition to its role for premature ejaculation.