In this study, electrochemical behaviors of formazans were investigated. The compounds contained CH3 and OCH3 groups at the o-, m-, and p-positions of the 1-phenyl ring and an OCH3 group at the p-position of the 3-phenyl ring. Their electrochemical behaviors, such as the number of electrons transferred, diffusion coefficients, and heterogeneous rate constants, were studied by cyclic voltammetry, ultramicrodisk electrode, and chronoamperometry. Possible mechanisms were proposed based upon the data obtained. There was a correlation between the absorption and electrochemical properties. A linear correlation was obtained between lambda(max) and E-red2 and Hammett substituent coefficients with E-red2 and k(s) values.