Abstract: On the basis of the field investigation of ammonia nitrogen contaminated by landfills in the Tianjin shallow groundwater,two representative water bearing media were sampled in the Tianjin coastal plain,and their and colloid's major physico-chemical properties were analyzed respectively. The dynamic curves and isotherms of ammonia nitrogen adsorption on the colloid of water bearing media were measured and the influence of particle size,zeta(ζ)potential and electrophoretic mobility on the adsorption were evaluated. The research results show that the kinetics of ammonia nitrogen adsorption on the colloid is the logarithmic curve,and the equilibrium period of the adsorption lasts for 20-24 hours,and all the adsorption isotherms are straight. In addition,It is found the colloids release out the ammonia nitrogen rather than adsorb the aqueous ammonia nitrogen when the ammonia nitrogen content is lower than a certain value. The smaller colloid particle is,the stronger the adsorptive capacity of ammonium ion on colloid. With increasing of the zeta(ζ)potential and electrophoretic mobility of colloid particle surface,the adsorptive capacity of ammonium ion on colloid goes up.