Alkaloids of sophora flavescens enteric-coated tablets was developed, and the method of drug release was established. Alkaloids of sophora flavescens enteric-coated tablets was developed using wet granulation and with Opaday OY-P-7171 as coating materials. The behavior of enteric coated tablets was evaluated in vitro by dissolution tests and determined by HPLC. Two parameters were critical in preparation of the tablet: the sorts and the amount of diluents. The coat weight was the significant factor of drug release. Alkaloids of sophora flavescens enteric-coated tablets prepared did not release matrine and oxymatrine in 0.1 mol L-1 HCl solution, but release matrine and oxymatrine rapidly in pH 6.8 phosphate buffer.