A Nafion/Fe3O4-CdTe/CdS-myoglobin(Mb)modified glassy carbon electrode（GCE) was prepared by immobilizing Mb on the electrode surface using Fe3O4 nanoparticles and CdTe/CdS quantum dots combining the advantages of film formation ability of Nafion.Cyclic voltammetric data showed that the immobilized Mb exerted a good direct electrochemistric behavior and a good stability with a pair of well defined and nearly reversible peaks at about-0.351 V in 0.1 mol/L pH 7.0 PBS corresponding to the characteristic peaks of the Mb heme Fe（Ⅲ)/Fe（Ⅱ) redox couples.The results indicated that the microenvironment of Nafion/Fe3O4-CdTe/CdS film could promote the direct electron transfer between Mb heme Fe（Ⅲ)/Fe（Ⅱ) and GCE and provide the matrix for the immobilization of Mb.The electrocatalytic ability of the immobilized Mb to the reduction of H2O2 was also investigated and the results suggested that the modified electrode could be used as a biosensor for the detection of hydrogen peroxide with high sensitivity（30.6 mA·L/mol),low detection limit（ 0.89 μmol/L,S/N=3) and rapid response.