Abstract: Carboxyl functionalized graphene was prepared by chemical dispersion and characterized by FT-IR and XRD. Composite membrane of carboxyl functionalized grapheme with chitosan (CS) was prepared via electrostatic self-assembly. The fluorescence properties of the composite film and the electro-catalytic oxidation-reduction properties of the composite membrane modified glassy carbon electrode for glucose were studied. Results showed that the functionalized graphene was successfully prepared and the composite membrane showed good photoluminescence performance. Glassy carbon electrode modified with the composite membrane showed good performance of electro-catalytic oxidation-reduction for glucose.