Various viologen derivatives were synthesized by Menshutkin reaction of 4, 4'-dipyridyl with various organic chlorides. Electrochemical behaviors of viologen derivatives were measured by the polarography and the cyclic voltammetry. The electrochromic phenomena have been studied in order to elucidate the substituent effects on the colored states. The linear relation between the first reduction potential of benzyl viologen derivatives and Hammett'sσ-value for substituent was found in KC1 aq. Change in the visible absorption spectra of colored states as a function of time was measured by the spectrophotometric method. The morphologies of deposited crystals on the display electrode were observed through the opticalmicroscope.