Hydrophilic graphene nanosheets were rapidly synthesized by reacting graphene oxide slice layer with poly（sodium 4-styrene sulfonate)（PSS) and simultaneously reduced with hydrazine hydrate under hydrothermal conditions.High resolving transmission electron microscopy（HRTEM) analysis indicated that the PSS modified transparent graphene nanosheets are entangled with each other and resemble rippled silk.The direct electrochemistry of hemoglobin（Hb) immobilized on the HAp and hydrophilic graphene（HG) composite film was studied and an amperometric biosensor of hydrogen peroxide was developed based on the direct electron transfer of Hb.Hb entrapped in HAp-HG film displayed a pair of well-defined redox peaks at about -0.295 V（vs-SCE) in 0.1 mol/L pH 7.0 phosphate buffer solution，which corresponded to the heme FeⅢ/FeⅡ redox couples.The resulting electrode showed an excellent electrocatalytic performance to the reduction of H2O2 with a fast amperometric response of about 5 s and could be used as a H2O2 biosenor with a lower detection limit of 0.58 μmol/L.