In　this　paper,　the　chitosan/starch　(CS/ST)　cast　films　were　prepared　using　AlCl3·6H2O　aqueous　solution　as　the　solvent　for　CS.　AlCl3·6H2O　was　retained　in　the　CS/ST　film　acting　as　the　plasticizer　and　glycerol　were　added　to　form　the　complex　plasticizer　with　AlCl3·6H2O.　The　effect　of　the　complex　plasticizer　of　AlCl3·6H2O　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　AlCl3·6H2O　aqueous　solution　was　a　better　solvent　for　CS　than　acetic　acid　aqueous　solution　which　is　the　most　commonly　used　solvent　of　CS.　With　AlCl3·6H2O　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　AlCl3·6H2O.　With　the　complex　of　AlCl3·6H2O　and　glycerol　as　the　plasticizer,　the　CS/ST　film　with　the　good　mechanical　properties　could　be　obtained.　©　2016,　Springer-Verlag　Berlin　Heidelberg.