The invention relates to a plaster for treating benign prostatic 
hyperplasia and belongs to a pure Chinese medicinal preparation. The plaster comprises the following components in part by weight: 1 to 5 parts of common monkshood mother root, 1 to 5 parts of kusnezoff 
monkshood root, 1 to 5 parts of rhubarb, 1 to 5 parts of 
cassia bark, 1 to 5 parts of nutgrass galingale 
rhizome, 1 to 5 parts of 
pangolin scales, 1 to 5 parts of root of red-rooted 
salvia, 1 to 5 parts of largehead atractylodes 
rhizome, 1 to 5 parts of glabrous greenbrier 
rhizome, 1 to 5 parts of 
centipede, 1 to 5 parts of Szechuan lovage rhizome, 1 to 5 parts of white paeony root, 1 to 5 parts of Chinese angelica, 1 to 5 parts of raw 
rehmannia root, 1 to 5 parts of atraotydin, 1 to 5 parts of Himalayan teasel root, 1 to 5 parts of glossy 
privet fruit, 1 to 5 parts of silktree albizzia 
bark, 1 to 5 parts of liquoric root, 400 to 600 parts of pure 
soybean oil and an appropriate amount of 
starch. A method for preparing the plaster comprises the following steps of: soaking the above compositions into the pure 
soybean oil; putting the medicaments into a sandy pot after soaking for enough days; decocting the medicaments over 
slow fire until the medicaments are dried and floated; filtering gruffs off with disinfected white cloth to prepare medicinal oil; making the ratio of the medicinal oil to the 
starch be 2:1; decocting the mixture over 
slow fire; continuously stirring the mixture until the mixture becomes sticky; dropping the mixture into water to become beads; collecting the beads into a porcelain container; and soaking the porcelain container into cold water for later use. The plaster has obvious effects of resisting 
inflammation, promoting 
urination and relieving pain because of compatibility of the Chinese medicaments, can be directly pasted on an affected part, and has 97.1 percent of significant efficiency.