Abstract: The preparation of Cassava Starch and Chitosan edible composite films were studied, and properties of the edible composite film were tested. Besides, Its application on Preservation of Mutton were observed. The results showed: when the ratio of 2% Cassava Starch and 2% Chitosan was 1.5:1,the properties of the edible composite film was the best. Its tensile strength, bibulous rate, floods gas rate and light transmittance of the film were 47.75±2.49MPa、77.4±2.3、0.355±0.056g?mm/h?m2?Kpa、70.4±1.02%, respectively. When it was applied to the preservation of mutton, the water loss rate, total volatile basic nitrogen（TVB-N）and TBARS of the mutton wrapped with the edible composite film were lower than that of the unwrapped mutton at 4 ℃ refrigerated condition, and the difference was significant（P<0.05）.