Abstract: To optimize the ethanol extraction of flavonoid from Dimocarpus longan Lour.Aril,ethanol concentration,temperature,water bath time,material-solvent ratio and extraction time were used as the criteria in the progressive single factor experiment.An orthogonal test of four factors and four levels was designed.The results showed that 85% ethanol,70℃,2.5h in a water bath and 1∶3 material-solvent ratio were the best conditions for the extraction process.