Objective:To optimize the extraction process of volatile oil in Aifu nuangong Granules.Methods:The particle size of medicinal materials

extraction time

and the solvent dosages were sysmatically stuied by the rate of extract volatile oil as marker.Results:The more effective way to extract volatile oil was effluent extraction with the particle size of medicinal materials as ten to twenty mesh

and with eight times amount of water under reflux for six hours.Conclusion:The particle size of medicinal materials and the solvent dosages showed greater effects than others on the extraction efficiency of volatile oil.