Abstract: The electrochemical co-deposition of histone (His), Ru(bpy)2(dppz)2+ (bpy = 2,2-bipyridine and dppz = dipyrido3,2-a:2,3-cphenazine) and multi-walled carbon nanotubes (MWCNTs) on an indium-tin oxide (ITO) electrode has been investigated by means of chronocoulometry, cyclic voltammetry, differential pulse voltammetry, fluorescence spectroscopy and scanning electron microscopy. The presence of His is found to promote the co-deposition of Ru(bpy)2(dppz)2+ and MWCNTs on the ITO electrode added at 1.2 V vs. Ag/AgCl. The prepared composite film shows two pairs of redox peaks controlled by surface electrochemical processes. Combined with the effects of His concentration and pH on the Ru(III)/Ru(II)-based redox reactions of the composite film, the electrochemical co-deposition mechanism of Ru(bpy)2(dppz)2+ and MWCNTs on the ITO electrode mediated by His is further illustrated. Under the optimal conditions, the oxidative charges of Ru(bpy)2(dppz)2+ in the composite film show a linear increase in the His concentration ranged between 0.01 ~ 0.2 mgL-1 and 0.2 ~ 5.0 mgL-1, the regression equations are described as Q/C = 3.24(0.27) 10-6 + 2.95 (0.09) 10-4 CHis/mgL-1 (R = 0.993) and Q/C = 5.92(0.25) 10-5 + 6.26 (0.62) 10-6 CHis/mgL-1 (R = 0.998). This study provides a new approach for the fabrication of redox-active inorganic bio-nanomaterials, as well as the immobilization and detection of proteins.