The herbal formulation (KH-204) mainly consisted of the fruits of Lycium chinense, Cornus officinalis, Rubus coreanus, Cuscuta chinensis and Schizandra chinensis. We investigated the effects of this herbal formulation on the penile erection and corpus cavernosum of spontaneous hypertensive male Rats (SHR). We used male SHR aged 16 weeks as a model of hypertension. The treatment groups received once a day oral doses KH-204 100 and 300 mg/kg per day for 4 weeks. Distilled water was administered in the control group. To investigate the penile erection, intracavernosal pressure (ICP) and mean arterial pressure (MAP) were recorded in all groups. We analyzed the distribution of NOS by immunohistochemical staining and the expression of nNOS, eNOS concentration in the isolated corpus cavernosum by western blotting. In the control group, ICP/MAP ratio was $14.9{pm}1.4%$ after pelvic nerve stimulation. ICP/MAP ratio was markedly increased in the treatment group with KH-204 100, 300 mg/kg, compared with control group. Immunohistochemical staining for NOS showed that eNOS and nNOS was stained as brown color. Compared with the control group, NOS activities of KH-204 100, 300 mg/kg were increased significantly. Also the penile expression levels of nNOS, eNOS in KH-204 100, 300 mg/kg treatment group were more increased significantly than control group by western blotting. This study showed that KH-204 enhances the penile erection and the level of eNOS and nNOS expression of penile corpus cavernosum of male SHR.