Abstract: Degradation coefficient of organic pollutant is one of the most important parameters,which can reflect the water quality.And it can be used to develop the water quality models and to calculate the water environment capacity.Its rationality directly affects the reliability of water environment capacity and water quality models.The degradation coefficients of COD,BOD and NH3-N in some rivers at home and abroad were summarized.And the main factors controlling degradation coefficient of organic pollutant were analyzed.It will be helpful for studying river self-purification rules,calculating the water environment capacity and making plan of controlling the total discharge quantity of pollutants.