Abstract: [Objective] To improve the effect of microencapsulated Clostridium butyricum used as feed additives. [Method] Orthogonal test was used for experimental design. The Clostridium butyricum was microencapsulated with mixture of sodium alginate, gelatin and starch at different concentrations. Biocompatibility, capacity, stability and proliferation of Clostridium butyricum in different microcapsules were studied. The microcapsules in gastro-intestinal fluid were used for artificial gastric juice test and artificial intestinal juice test. High temperature test and bile salt test were also conducted. [Result] The wall material and Clostridium butyricum had good biocompatibility. The Clostridium butyricum proliferated well in the microcapsules, and concentration of live bacteria was increased from 1.3×108 CFU/mL to 1.3×1010 CFU/mL within medium 3 （embedding rate, 83.4%） and from 3.3×108 CFU/mL to 4.9×109 CFU/mL within medium 4 （embedding rate, 99.5%）. The embedding medium 4 was the best, and its microcapsules had good stability and strong heat resistance. After these microcapsules were treated in artificial gastric juice for 2 h, transmission rate was 99.5%. However, after further treatment in artificial intestinal juice for 2 h, the transmission rate declined to 29.7%, which shows good enteric solubility. The logarithm of Clostridium butyricum in microcapsules was reduced by 1.1% in artificial gastric juice and 1.5% in artificial intestinal juice. The bacteria concentration after the trial was not significantly different from that before the trial. The acid tolerance and bile salt tolerance were increased significantly, compared with the control group. [Conclusion] Microencapsulation increases survival rate of Clostridium butyricum and has good effect on proliferation and stability.