|Cystitis is an inflammation of the bladder lining. The most common mechanism of cystitis is bacterial infection through the urethra. The symptoms are urodynia, dysuria, pyuria and hematuria. In Korean Medical theory, acute hemorrhagic cystitis results from Heat-poison(熱毒) in urinary bladder. That is, Heat-poison is accumulated in Lower Burner(下焦) and results in cystitis. So, we treated for cystitis with Heat-cooling and Dampness-irrigating(淸熱利濕) formula, for example, Yongdamsagan-tang. In this study, we had a case of a cystitis patient who had severe hematuria. The patient was treated with Yongdamsagan-tang without any antibiotics. The case showed favorable results in symptom, urinalysis and blood test. All the symptoms, urinalysis and blood test results were recovered after 5 days medication. It is suggested that acute hemorrhagic cystitis can be treated with Heat-cooling and Dampness-irrigating formula like Yongdamsagan-tang.