Abstract: To study the feasibility and advantage of extraction of multiple components from Polygonum cuspidatum with mixed solvent,chemical components of Polygonum cuspidatum were extracted by petroleum ether, ethyl acetate, 70% ethanol and different mixed solvent. The mixture of 70% ethanol and ethyl acetate was selected as extraction agents to investigate the effects of extraction time, temperature and ratio of volume to weight on extraction. According to the yield of polydatin and emodin,the optimal extraction conditions were determined to be:solid-liquid ratio of 1:12.5,extraction time of 2 h and temperature of 85 ℃.Using mixed solvent can enhance the extraction efficiency of constituents with different polarity.This method provided a new way for the extraction of multiple components from traditional Chinese Medicine.

Key words: mixed solvent, multipolar components, extraction, Polygonum cuspidatum