To investigate the effect of manganese intermediates in situ formed on the oxidation of anti-biocide triclosan by potassium permanganate, experiments were conducted to examine the effects of some ligands as well as Mn(II) on the oxidation of triclosan by potassium permanganate under the condition with potassium permanganate in excess over a wide pH range. The results showed that the degradation of triclosan followed the second-order kinetics and the rate constants increased with the increase of pH and reached the maximum near the pK_a (8.1) of triclosan, after which they decreased gradually. Both selected ligands and the background matrices of nature waters could significantly enhance the oxidation dynamics of triclosan by potassium permanganate via the involvement of stabilized manganese intermediates. The analysis by the UV-vis spectrophotometer scanning confirmed the formation of soluble Mn(III) in the presence of ligands, which would otherwise disproportionate spontaneously to yield solid MnO₂. Also, these results suggested a catalytic role of Mn(II) in the oxidation of triclosan by potassium permanganate.