AIM: To study the transdermal permeability of ephedra extract. METHODS: With Valia Chien diffusion cell to the transdermal experiments are used to observe the effect of different factors on the transdermal permeability. RESULTS: Its transdermal resorption constant increased with the increase of the concentration of ephedrine and ephedra extract. pH value of the diffusioin medium could influence ephedrine permeability. CONCLUSION: The result can offer reference in preparation for Ephera (targeting drug delivery system) (TDS).