In this study, myoglobin (Mb) immobilized on carbon paste electrode that modified with zirconia nanoparticles to construct a novel biosensor for hydrogen peroxide (H2O2). The prepared nanoparticles and electrodes were characterized by transmission electron microscope (TEM) and atomic force microscope (AFM). The resulting electrode displayed an excellent redox behavior for the myoglobin. The myoglobin showed a quasi-reversible electrochemical redox behavior with a formal potential of -0.428 V (versus Ag/AgCl) in 0.1 M PBS solution at pH 7.0 and temperature 25°C. The linear range of this biosensor for H2O2 determination was from 20 to 450 μM Moreover, the modified electrode demonstrated additional improved electrochemical properties, such as good reversibility (ipc/ipa ≈1) and high selectivity good stability and repeatability.