Abstract: The research objects are different kinds of soils including clay,heave silting clay,silting clay,clay silt and sand clay in Beijing area. The dispersion coefficients of different kinds of soils are obtained through hydrodynamic dispersion experiment indoors. The soil column measuring dispersion coefficient is also experimented on breakthrough curve of ammonia nitrogen and organic matter. The results show that the breakthrough curve of ammonia nitrogen and organic matter in clay,heave silting clay and silting clay is divided into two phases,but the breakthrough curve of sand clay gradually rises and stays stable in the end.