A medicine for curing chronic prostatitis and the preparation method relate to a Chinese traditional medicine and the preparation method; the medicine is made of 15 Chinese traditional medicines such as cocktree bark, milk vetch root, hedyotis, epimedium herb, cowherb seed, corydalis turtschaninovii, etc.; these medicines are extracted by alcohol and water and then condensed to the medicine; the medicine can be made into pill, troche, capsule or mixture. The prevent invention of the medicine has the functions of clearing heat, promoting diuresis, removing blood stagnation and tonifying kidney. The present invention can be used for the diseases of frequent urination, urgent urination, painful urination, continuous urination, white secretion flowing through the urinary duct, dull pain or ache in perineum, pubis upper part and sacral region of waist and sexual hypo-function. The curative effect is steady and the medicine is innocuous and has no side effect.