To expose the kinetic law of enrofloxacin oxidation by potassium permanganate in aquatic environment, the article studied the rate constant of reaction, and simultaneously investigated the reaction influencing factors such as potassium permanganate dosage, pH value and temperature. The results showed that the oxidation reaction of enrofloxacin by potassium permanganate in aqueous solution followed second-order kinetics. The reaction rate constant was observably influenced by the three effect factors. The reaction rate increased with the increasing of temperature and potassium permanganate dosage. Under neutral condition, the reaction is easily conducted at the acidic and basic condition. The reaction activation energy Ea is 53.27 kJ·mol-1,slightly lower than that of the common chemical reaction, which reveals that the oxidation reaction between enrofloxacin and potassium permanganate is feasible under usual water treatment condition.