To discover the kinetic law of ofloxacin oxidation by potassium permanganate in aquatic environment, this article studied the rate constant of reaction and the reaction influencing factors such as potassium permanganate dosage, pH value and temperature. The results showed that the oxidation reaction of ofloxacin by potassium permanganate in aqueous solution followed second-order kinetics. When potassium permanganate was excessive, pseudo-first-order rate and concentration of potassium permanganate followed the equation: Kobs=0.000 092［KMnO₄］-0.002 72. The second-order reaction rate constant was influenced by pH values. The rate of ofloxacin oxidation by potassium permanganate increased with the increasing of temperature, and the reaction activation energy Ea=30.463 3 kJ·mol-1,which revealed that the oxidation reaction between ofloxacin and potassium permanganate was feasible under usual water treatment condition.