Objective: To prepare Gualou-Xiebai intragastric floating pellets(18-24 mesh)by extrusion-spheronization method, and investigate their release characteristics in vitro. Methods: Using the floating time of pellets as indicator and the percentage of microcrystalline cellulose (MCC), octadecanol, hydroxypropyl methylcellulose- K4M (HPMC-K4M)and HPMC-K15M in the solid excipients of the prescription as affecting factors on the basis of single factor experiments, the formulation was optimized by star design-response surface optimization method. Taking the content of 3, 29-dibenzoyl karounitriol in the release medium as the index, the release rate of the pellets in vitro was determined and the release characteristics were explored. Results: The optimum prescription of these pellets was as follows: Gualou-Xiebai dry extract 25 g, MCC 6 g, octadecanol 11 g, HPMC-K4M 3 g, HPMC-K15M 11 g, 70% ethanol solution as wetting agent, and 40% polyvinylpyrrolidone(PVP-K30)solution as binder. The floating time in vitro of the pellets prepared by this prescription was 12 hours, and the cumulative release rate data fitted well with the first-order release model (r>0.97). Conclusion: The Gualou-Xiebai intragastric floating pellets prepared in this study had good floating property and sustained release effect, indicating that the preparation method is feasible.