Abstract: Phycocyanin-chitosan composite films were prepared by adding phycocyanin using chitosan as a film-forming material. The effects of phycocyanin concentrations on physicochemical,mechanical properties,and antimicrobial properties of the composite film were studied. Results showed that water vapor permeability and tensile strength of the film decreased whereas the opacity,antimicrobial activity and elongation at break increased significantly with the increase of phycocyanin(0.5%~1.0%,w/v). When the phycocyanin addition ratio was 1.0%,the surface and internal structure of the composite film were more homogeneous and denser,with the largest opacity(3.927 Abs₆₀₀·mm^-1),elongation at break(79.73%),and the lowest water vapor transmission coefficient(1.273×10^-10g·m^-1·s^-1·Pa^-1).The diameter of 1.0% composite membrane against E. coli was the largest,22.36 mm. This study can provide theoretical basis for the application of phycocyanin-chitosan biodegradable composite films.