Electrocodeposition of poly(neutral red) (PNR) and hemoglobin (Hb) can be easily prepared on electrode surface with multi-walled carbon nanotubes (MWCNT). Morphology of PNR-Hb-MWCNT hybrid nanocomposite is studied by SEM, AFM and electrochemical methods. It shows eletrocatalytic activity to hydrogen peroxide (H2O2) with high current response and low overpotential. Amperograms presents a high sensitivity of 700.8 μA mM-1 cm-2 to H2O2 (Eapp. = -0.25 V). Linearity is estimated in a concentration range of 1×10-5-1.33×10-3 M with a detection limit of 5×10-7 M (S/N = 3). Hybridization and activity of PNR and Hb can be effectively enhanced by MWCNT. The hybrid composite can be applied for determination of H2O2.