Abstract: In this study,the synthetic tachyplesin peptides were used as core material.Microcapsules containing tachyplesin were prepared by a complex coacervation method with chitosan and sodium alginate as wall material.The wall material concentration,the ratio of wall to core material,the capsule temperature,p H and other factors were investigated to optimize the preparation process of tachyplesin microcapsules.Embedding ratio and particle size distribution were studied using single factor and orthogonal experiments to determine optimal conditions.Morphology and particle size distribution of microcapsules were studied in the optimization process.At the same time,the sustained release effect of tachyplesin microcapsules was studied in simulated gastric and simulated intestinal fluid,and the comparison of antimicrobial activity and stability of the microcapsules with the non encapsulated peptide were also studied in protease environment.The best technological conditions were chitosan and sodium alginate concentration of 1.5%,wall / core material ratio of 8∶1,the capsule temperature of 45 ℃ and the encysted p H of 5.0. Under these optimized conditions,encapsulation efficiency was 84.56%. Tachyplesin microcapsules were regularly spherical,and the particle size was mainly distributed in the 40 ~100 μm region,the average particle diameter was 76.58 μm.The release rate of tachyplesin peptide microcapsules reached 38.54% in simulated gastric fluid,and 80.68% in simulated intestinal fluid.The antimicrobial activity of the tachyplesin microcapsules was 80.6% of the non- embedded peptide.Microencapsulated tachyplesin with protease tolerance were more stable than non encapsulated tachyplesin.