Objective: To prepare clinopodii saponin microspheres with acrylic acid resin Ⅱas material and evaluate its release in vitro. Method: Clinopodii saponin microspheres were prepared by spray drying technique.Preparation technology was optimized by orthogonal test design with appearances

yield and entrapment efficiency as indexes.In vitro drug release of microspheres were carried out in two different media of artificial gastric juice and artificial intestinal fluid. Result: Clinopodii saponin microspheres showed good spherical geometry

smooth surface and suitable size distribution under scanning electron micrographs.Yield was(97.53±2.39)%

entrapment efficiency was (92.87±4.2)%.Little release of clinopodii saponin microspheres were observed in artificial gastric juice.In artificial intestinal fluid

release of clinopodii saponin was less than 30% in 1 h

close to 60% in 3 h

then release slowly

more than 80% in 8 h. Conclusion: Prepared clinopodii saponin microspheres had good appearances

high yield and high entrapment efficiency.