目的　探索包裹破伤风类毒素蛋白 (TT)的聚乳酸 (PLA)及聚乳酸 /聚乙醇酸 (PLG)共聚微球的制备及其体外释放特性。方法　采用溶剂蒸发技术 ,先以一种小分子量生物染料 伊文思蓝为包裹物模型 ,通过显微镜观察和比色分析探索微球的制备特性和最佳条件。在此基础上制备包裹TT的PLA和PLG微球。结果　微球的制备过程中存在着内水相蛋白朝外水相的流失 ,当聚合物浓度加大到 2 5 %～ 30 %时可使蛋白流失大大减少。包裹蛋白在微球中的分布与微球粒径的重量分布成正相关关系 ;随着微球粒径的增大 ,微球所载蛋白的体外释放高峰期延迟。结论　通过本模型条件可制备外观高质量的微球 ,并可通过制备不同粒径大小的微球来控制包裹蛋白在体外和体内的释放高峰期 Objective To investigate the preparation and in vitro release characteristics of tetraploid tetanus toxoid (TT) -containing polylactic acid (PLA) and polylactic / polyglycolic acid (PLG) microspheres. Methods Solvent evaporation technique was used. The first was a small molecular weight Evans blue as a coating model. Microscopic observation and colorimetric analysis were used to explore the preparation properties and optimum conditions of microspheres. On this basis, PLA and PLG microspheres encapsulating TT were prepared. Results The preparation of microspheres had the loss of the aqueous phase of the inner aqueous phase. When the concentration of the polymer was increased to 25% ~ 30%, the protein loss could be greatly reduced. The distribution of the encapsulated protein in the microspheres was positively correlated with the weight distribution of the microspheres. With the increase of the size of the microspheres, the peak of in vitro release of the proteins contained in the microspheres was delayed. Conclusions The microspheres with good appearance can be prepared by the conditions of this model, and the release peak of encapsulated protein in vitro and in vivo can be controlled by preparing microspheres with different particle sizes