Factors which influence the extraction of Chinese materia Medica were comprehensively studied,by ex-tracting each single herb component in the compounded preparation Sinitang as the sample,and determiningthe extraction rate as well as the content of main active principle in each extract as the evaluation criteria. Thegeneral ru1e for the extraction of single herb material was then investigated. The results indicated that it isbetter to desigm the experiment in accordance with it's characteristic object with...