Adsorption of thiocyanate anions (SCN-) induced by electrochemical polarization on active carbon felt (ACF) electrode was measured in a three-electrode cell by UV spectroscopy for the application of the electrosorption technique in the removal of SCN- in water. Positive polarization of the ACF electrode causes a dramatic increase in the adsorption of SCN- and negative polarization causes desorption of most of SCN- from the ACF electrode. The reversibility of electrosorption is remarkably affected by current intensity, solution pH, and the co-existed ions. The fully reversible electrodesorption of SCN- occurs in basic solution with pH 9.68. Electrochemical oxidation of partial SCN- decreases this reversibility under stronger polarization. The stronger adsorption of SCN- on open circuit in acid solution and the competition of [image omitted] with SCN- also results in the decreased reversibility of electrosorption.