Abstract: The preparation of IgY-chitosan microencapsulation and its sustained-release capacity were studied.The IgY-chitosan microencapsulation was prepared by ionic crosslinking method taking chitosan as the wall material and sodium tripolyphosphate as the crosslinking agent.Chitosan ( W/V) , chitosan /TPP ( w /w) and IgY concentration ( W/V) were recognized as main factors that affect the entrapment efficiency and the loading efficiency of the chitosan microencapsulation.Response surface analysis was used to optimize parameters of the preparation.It was found that the optimal conditions for the entrapment efficiency and the loading efficiency of chitosan microencapsulation were 0.23 g /100 mL of chitosan, 4∶1 of chitosan /TPP and 2.46 mg /mL of IgY.The actual value of the entrapment efficiency and the loading efficiency of chitosan microencapsulation were respectively 93.26% and25.64% under this conditions and the relative error was little when compared to the theoretically predicted value.The chitosan microencapsulation was characterized and showed that the mean particle size was about 2.16μm and the zeta potential was 26.20 mV analyzing by a Zetasizer. In the SGF and PBS, IgY- chitosan microencapsulation showed a good sustained- release performance for 6h. The activity of IgY in SGF was protected after microencapsulation.