In this paper, the chitosan/starch (CS/ST) cast films were prepared using AlCl3 center dot 6H(2)O aqueous solution as the solvent for CS. AlCl3 center dot 6H(2)O was retained in the CS/ST film acting as the plasticizer and glycerol were added to form the complex plasticizer with AlCl3 center dot 6H(2)O. The effect of the complex plasticizer of AlCl3 center dot 6H(2)O and glycerol on the crystalline, thermal stability, and mechanical properties of CS/ST films was studied by X-ray diffraction, thermal gravity analysis, and tensile testing, respectively. The results showed that AlCl3 center dot 6H(2)O aqueous solution was a better solvent for CS than acetic acid aqueous solution which is the most commonly used solvent of CS. With AlCl3 center dot 6H(2)O aqueous solution as the solvent, the thermal degradation of CS and ST in the dissolving process was weakened. Glycerol could form the synergism plasticizing effect with AlCl3 center dot 6H(2)O. With the complex of AlCl3 center dot 6H(2)O and glycerol as the plasticizer, the CS/ST film with the good mechanical properties could be obtained.