With a long history Yunnan Baiyao Plaster has long enjoyed high reputation both at home and abroad for its define functions of stopping bleeding, activating blood circulation, dispersing blood clots, diminishing inflammation and swelling, discharging pus and toxin and etc. Because of the inconvenience of its powder preparation, a plaster form has been prepared following the tincture form. The difference between the tincture and the plaster is that the tincture has evident action of stopping internal and external haemorrhege, while the plaster exerts outstanding actions of easing pain, diminishing swelling, dispersing clots and dispelling rheumatism. Yunnan Baiyao Plaster is used for the treatment of injuries in closed joints and soft tissues, pain due to extravasated blood and swelling, rheumatism pain and muscle ache. In addition, thousands of people using the plaster in treatment have offered written or oral reports on good curative effect of the plaster. Associate professor Cai Xilin of Jiangxi Medical College conducted studies with radioelement 32p of the influence of the plaster on capillacy permibilities of mice skin and on blood flowing in tissues of mice skin and also studies with radioelement 86Rb of the influence of the plaster on swelling in rats feet and on the phagocytosis of abdominal macrophage of mice. The study results along with the result of pharamacological study of diminishing inflammation and swelling by Yunnan Baiyao Factory show that Yunnan Baiyao Plaster has functions of improving capillacy permiberation of topical skin, increasing blood flow of topical tissues, promoting proliferation and activation of macrophage, diminishing inflammation and swelling, activating blood circulation and dispersing blood clots. In September,1984, a technical appraisal of Yunnan Baiyao Plaster was made by Yunnan Health Department and Yunnan Pharmaceutical Administration Bureau, and the experts and technicians concerned unanimously affirmed the quality and the curative "effects of Yunnan Baiyao Plaster". Yunnan Baiyao Plaster began to be produced in Yunnan Baiyao Factory in 1985 with the approval of Yunnan Health Department.