OBJECTIVE:To prepare Yinxingye extract pellets and study its in vitro drug release rate.METHODS:The Yinxingye extract were coated with 3 coating materials(opadryⅡ,Eudragit L30D-55 and Eudragit S 100,respectively)to be prepared into pallets by centrifugalized palletizing method;and the 3 different coated pallets were prepared into mixed pallets in an pre-designed ratio.The in vitro release of the 3 coated pallets and the mixed-coated pallets were determined by changing the pH-gradient of media(0.1 mol?L-1 hydrochloric acid,pH 5.8 PBS,pH 7.2 PBS).RESULTS:The pallets coated with 3 different coating materials released quickly in 0.1 mol?L-1 hydrochloric acid,pH 5.8 PBS and pH 7.2 PBS,and the pellets with mixed coating materials had a sustained release until a complete release within about 8 h in pH gradient-changed media.CONCLUSION:The preparation process is feasible and provides theoretic basis for industrial production.