Abstract: The extraction processing and stability of the resveratrol from Polygonum cuspidatum were studied in this research. The resveratrol is unstable against light, heat, wet-heating and oxidant. On the base of experimental analysis, the extraction rate of reflux extraction, continuous fixed bed extraction and ultrasonic extraction were 0.201%, 0.423%, 0.513%. And continuous fixed bed extraction is optimized by orthogonal test method. The optimum conditions were obtained as follows: the concentration of the ethanol 30%, extracting speed 8 ml/min·kg, immersion time 12 h and the solvent 9 times of the material.

Key words: Polygonum cuspidatum, resveratrol, extraction