Abstract: A new compound material,Al2O3/PEG sol-gel,was prepared,and its structural composition and specific properties were characterized by FT-IR,SPM and etc.As shown by experimental results,large amounts of hydroxyl groups and hydrogen bonds were found in the structure of the composite film,and interpenetrating network structure was formed by the two components.The binary property of rigidity and flexibility of this new compound material,made it a desirable immobilizing material to be used in fabrication of biosensors.PEG as a polar high polymer,when formed sol-gel compound material with Al2O3,acted to accelerate the reaction and to prevent the material from cracking.In addition the Al2O3/PEG sol-gel compound material showed good biocompatibility and high stability toward enzymes.Biosensors made by immobilizing enzymes in this new material showed its specific features of good reactive activity,high sensitivity and prominent stability.