With 1-Pyrenebutyric acid (PBA) and multiwalled carbon nanotubes (MWNTs), glassy carbon electrode modified was successfully prepared. In phosphate buffer solution (pH 7.0), the direct electrochemistry of cytochrome C (Cyt C) was realized. In the cyclic voltammetry experiment two pairs of redox peaks of Cyt C were observed at 0.018 V and –0.314 V (vs. SCE), respectively. The redox reaction at 0.018 V was diffusion controlled, while the redox reaction at –0.314 V was adsorption controlled. In the phosphate buffer solution (pH 7.0), the direct electrochemistry of cytochrome C (Cyt C) was realized. In the cyclic voltammetry (PBA) and multiwalled carbon nanotubes (MWNTs), glassy carbon electrode modified was successfully prepared. experiment two pairs of redox peaks of Cyt C were observed at 0.018 V and -0.314 V vs. SCE, respectively. The redox reaction at 0.018 V was diffusion controlled, while the redox reaction at -0.314 V was controlled controlled.