In order to analyze principles of taking concoction and make clear the origin of contraindication against five pungent vegetables, the regulations of Guizhitang prescription in "Shanghanlun" the twelfth article and "Wushierbingfang", "Wuweihandaiyijian", "Jinguiyaolue" were researched. Four principles of taking concoction were put in order; strengthening the effect of concoction by eating hot rice gruel and wearing bedclothes, preventing decline of drug effect by food regulations, optimization of elution and effect of material herbs by crushing, low heating, determination of administration time based on manifestations of drug effect by sweating and its aspect. These principles and methods of taking concoctions were developed from boiling to simple processing of material herbs, contraindication in the middle of taking concoction and perspiration by wearing bedclothes and eating hot rice gruel in order from the analysis of medical literatures. The contraindication against pungent vegetables were generalized in early Dong-Han dynasty already, and the five pungent vegetables were inferred as Allium tuberosum, Allium bakeri regel, spring onion, wild rocambole and garlic in medical context to the exclusion of religious idea. The reason of prohibition against five pungent vegetables could be interpreted as optimization of therapeutic effects by pharmacological control of pungent ingredients because the healthy qi damage and evil qi retention were resulted from destroying of harmonious ying and wei by overeating pungent vegetables during disease state. Conclusively the regulations of Guizhitang prescription referred to taking concoction in "Shanghanlun" fulfilled their functions to maximize pharmacological effects through various ways inside and outside and these reasonal principles of taking concoction has been influenced over the traditional medical practice deeply.