Resonance Raman scattering (RRS) and absorption spectroscopies were applied to elucidate one- and two-electron oxidation processes of 3,3＇,5,5＇-tetramethylbenzidine (TMB) in organic solvents such as n-butyronitrile. The RRS spectra of a charge-transfer (CT) complex and a dication (TMB2+) were characterized. The CT-complex was found to give a CH out-of-plane bending band near 955 cm(-1), which is absent in the RRS spectrum of the dication. A structural model was proposed for the CT-complex, in which the dication is converted to a neutral state through deprotonation and operates as an electron acceptor. RRS spectral changes observed during one-electron oxidation in n-butyronitrile at 0.60 V (vs. Ag/Ag+) were analyzed in order to propose a reaction scheme, which leads to the formation of the CT-complex. When a sample solution was flowed through a thin-layer electrochemical cell at 0.95 V (vs. Ag/Ag+), an electrodeposition process takes place, forming a CT-complex film at the electrode surface. On the other hand, when the solution was not flowed through the cell, an oxidation reaction occurs in the solution, resulting in the formation of the dication.