Objective:To compare the weight of macroporous resin separation parts and its HPLC profile with the different Chinese herbal pieces from Rheum palamatum L.

and to explore the effective substance of the processed herbal medicine. Method: 75% ethanol was used for extraction. After the separation by the macroporous resin

four parts were analyzed by HPLC analysis. Result:The total extraction weight from high to low is no-parched

liquored>vinegar-baked>braising with liquor>charred. The mass of 50% ethanol elution part is highest in liquored

vinegar-baked and charred. The 20% and 50% ethanol elution part have the same weight in no-parched

however

the braising with liquor represent a degressive tendency. HPLC results demonstrate that the 20%

50% and 95%ethanol elution parts differences are remarkably. Conclusion: With the increased processing conditions

the composition of chemical constituents and content in different pieces has obvious changed. Extractions weight and HPLC results indicate that the changes of chemical constituents may result in different property among different Chinese herbal pieces from Rheum palamatum L.