The paper aims to investigate the effects of D-fructose and glucose as plasticizers upon properties of corn starch-chitosan composite films. The gelatinized corn starch solution was blended with the chitosan solution, 5%, 20%, 35%, 50% and 65% (mass fraction) of D-fructose of glucose were added, respectively; and then they were homogenized and cast into a film. The mechanical properties of the film were measured, and morphology properties, contact angle, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were used for characterization. The film-forming materials had good compatibility, the concentration of plasticizer was increased from 5% to 65% while the thickness of the film was increased, but the tensile strength of D-fructose and glucose plasticized films was decreased from 73.99, 70.88 MPa to 18.08, 40.53 MPa, respectively. The elongation at break of D-fructose plasticized film revealed an increasing trend, up to 19.03% at addition of 65%; while the glucose plasticized film displayed a decreasing trend. The thickness and tensile strength of the two plasticized films are similar at the same concentration, but the D-fructose plasticized film has high elongation at break and good hydrophilicity. It is more suitable to be used as a plasticizer in the preparation of composite films.