tThe objective of the present work was to improve blown film extrusion processability and properties ofthermoplastic starch (TPS) film by incorporating plasticized chitosan, with a content of 0.37–1.45%. Theeffects of chitosan on extrusion processability and melt flow ability of TPS, as well as that on appearance,optical properties, thermal properties, viscoelastic properties and tensile properties of the films wereinvestigated. The possible interactions between chitosan and starch molecules were evaluated by FTIRand XRD techniques. Chitosan and starch molecules could interact via hydrogen bonds, as confirmed fromthe blue shift of OH bands and the reduction of V-type crystal formation. Although the incorporationof chitosan caused decreased extensibility and melt flow ability, as well as increased yellowness andopacity, the films possessed better extrusion processability, increased tensile strength, rigidity, thermalstability and UV absorption, as well as reduced water absorption and surface stickiness. The obtainedTPS/chitosan-based films offer real potential application in the food industry, e.g. as edible films.