ABSTRACT
Experimental studies showed that the water extract of rhubarb had low content of anthraquinone and a strong purgative while the alcohol extract a high content of anthraquinone and was free of purgative action,even tannin was eliminated.The purgative action of the water extract was also last when mixed with alcohol extract. The experimental results coincide with the traditional experience in Chinese medicinal theory:"the fresh Rhubarb has a purgative action while rhubarb prepared with wine can promote blood circulation and remove blood stasis."However, from the angle of anthraquinone and tannin, the explanation is unreasonable. It is indicated that the purgative action of rhubarb is greatly influenced, even disappears when prepared with alcohol. So, attention should be paid in the preparation process of Chinese patent drugs containing rhubarb.