Objective:To study the skin local pharmacokinetics of Sinomenine Patch.Method:The microdialysis technology was used as sampling tool combined with isotope tracer method.The HPLC-UV detector and liquid scintillation counter was selected as detection tool.The relative loss（RL） was determined by using delivery method.The liner probes were implanted into the subcutaneous tissue to determine the real-time

in vivo concentration of sinomenine.The skin microdialysis sample was calibrated by relative loss and fitted with compartment and non-compartment model.Result:The compartmennt model was not the good model.The non-compartment parameters showed that the maximum skin concentration appeared at about 6 h after drug administration and the mean residence time（MRT） was about 18 h.Conclusion:The microdialysis technology could collecte the local skin pharmacokinetics characteristics of transdermal administration and of sinomenine was the appropriate study tool.