An ITO electrode was coated by a Nafion film incorporating Ru(bpy)(3)(2+) complex as redox centers either by mixture casting method, adsorption method, or swelling method and the electrochemical reactivity of the modified electrode was determined by the in-situ spectrocyclic voltammogram (SCV) in a sodium perchlorate aqueous solution at pa 1.2. A modified Poisson statistics equation was used to estimate the charge transfer distance (Re) between the Ru(bpy)(3)(2+) complexes. The estimated charge transfer distances for the electrodes prepared by swelling method (Ro = 1.63 nm for the electrode modified in M/W 1:10, and 1.69 nm in M/W 1:2) and adsorption method (Ro = 1.61 nm) were longer thant that for mixture casting method (Ro = 1.5 nm). Based on the different procedure of Ru(bpy)(3)(2+) complex incorporation in the Nafion film, the reasons that affect the apparent charge transfer distance were discussed.