Abstract: OBJECTIVE To investigate in vitro transdermal permeation ability of oxymatrine gel and its pharmacokinetics in rats. METHODS The skin permeation ability of oxymatrine was evaluated by using Valia-Chien permeation cells with isolated rat skin. The concentration of drug was determined by HPLC. The preparation formulation of the gel was optimized which took the permeation amount as the index. RESULTS The accumulative permeation amount of the optimal formulation of gel was (18.094±1.253)mg·cm^-2 in 12 h. The pharmacokinetic parameters showed that the AUC_(0-t) of transdermal administration was 1.9 times of iv adminirtration. CONCLUSION Oxymatrine gel has good absorption and long-time substained release, it can be developed as a novel transdermal preparation.