In this work chitosan-PE bi-layer films were prepared by casting method. The structure and thermal stability were analyzed to observe the existence of new chemical bonds and adhesiveness between chitosan-PE films. The films structure and thermal stability were observed by infrared spectroscopy coupled with scanning electron microscope and thermogravimetric analysis coupled with differential scanning calorimetry,respectively. The results showed that no new chemical bonds were formed between chitosan and PE film surface,and the structure of PE film was not influenced by chitosan coating. However,the adhesiveness of films between chitosan and PE film was fine.