Objective:To study on effects of in vitro percutaneous penetration of different penetration enhancers for three active ingredients from Fufang Kali Ziran gel

and to screen out effective transdermal absorption enhancers. Method:In vitro transdermal test was used by modified Franz diffusion cell method and in vitro rat skin

effect of cumulative penetration volume and penetration rate from transdermal absorption enhancers for three active ingredients(psoralen

isopsoralen and osthole) was determined by HPLC. Result:Different enhancers were found to have different degree in vitro penetration enhancing effect on psoralen

isopsoralen and osthole in Fufang Kali Ziran gel

determined 2% azone had optimum promoting effect as enhancers to three active ingredients. Conclusion:2% azone could promote effective penetration of three active ingredients from Fufang Kali Ziran gel. This process of penetration absorption could be in line with Higuchi equation.