Abstract: Polydimethyldiallylammonium chloride (PDDA) was used as functional polymolecules to modify oxide of graphene, and a composite material of PDDA-graphene (PDDA-G) was prepared by reduction. A dispersion of PDDA-G in water was easily prepared. By the electrostatic force, graphene-enzyme nanomultilayers modified electrode was fabricated by alternate self-assembling of PDDA-G and horseradish peroxidase. This modified electrode was used as an enzyme biosensor which displayed rapid amperometric response, when used in the determination of hydrogen peroxide. Linearity range of hydrogen peroxide was found between 1.0 μmol·L-1 and 155.0 μmol·L-1 with detection limit of 0.3 μmol·L-1. Precision of the method was tested at the concentration level of 50.0 μmol·L-1 hydrogen peroxide solution for 8 determination, value of RSD found was 2.6%. The proposed method was applied to the determination of H2O2 in food samples, giving results in consistency with the values obtained by the GB method.