Abstract: In this paper, piercing-solidifying method was applied to obtain the capsules of surfactin with sodium alginate as wall material and calcium chloride as solid solvent. On the basement of one-factor experiments, four factors including calcium chloride and sodium alginate concentration, ratio of core to wall, temperature were optimized by the method of response surface. The performance of all factors was evaluated by the microencapsulation efficiency. The results showed, under the condition of calcium chloride concentration 2%, temperature 49℃, the proportion of sodium alginate to surfactin 1 ∶2, sodium alginate concentration 2.4%, the microencapsulation efficiency reaches 87.6%, the load ratio of drug reaches 12.5%. The release rate of Surfactin from the microcapsule reached 91.7%, which showed that it had good slow-release effect.