Bombyx mori Sericin films were prepared with PEG-DE as cross linking agent. The main physical properties, structure characteristics, cytotoxicity and cell proliferation of sericin films were measured and analyzed. The result showed that sericin films prepared by cast method containing 30-40% of PEG-DE, showed good mechanical properties. PEG-DE caused the changes of the condensed structure of sericin films. The films prepared from sericin extracted both from silk-gland and cocoon shell showed good cytocompatibility. Silk sericin films with PEG-DE had no obvious cytotoxicity to cells.