The degradable packaging composite films made from chitosan(CS) and soy protein isolate(SPI) were developed. The structural features of CS/SPI composite films were investigated by mean of FTIR, XRD and SEM. The tensile properties and light transmission properties of the films were tested and analyzed. The results showed that certain interaction exists between CS and SPI; when the mass fraction of SPI is 10%, the packaging composite film has higher tensile properties than that of chitosan film with slightly lower light transmittance than chitosan film.