Abstract: Temperature variation can change water environment, which causes the variation of adsorption and desorption of the ions in surroundings. The capability of preserve moisture and fertility in sand is worse than that in the other soil. Once the pollution of ammonium nitrogen (N H₄⁺-N) happens in sand, the problems will be more serious. To provide theory and technology for preventing the pollution of ammonium nitrogen (N H₄⁺-N) in sand, the authors studied the adsorption and transformation characteristics of ammonium nitrogen (N H₄⁺-N) in coarse sand, medium sand and fine sand under different temperature conditions, based on the static adsorption experiment. The results show that in the setup temperature range, the lower the temperature is, the higher the adsorption capacity of ammonium nitrogen (N H₄⁺-N) is, which indicates that the adsorption of ammonium nitrogen (N H₄⁺-N) is inhibited by high temperature. And it is the cause that low exotherm of adsorption process can reduce the capability of equilibrium adsorption for ammonium nitrogen (N H₄⁺-N). The transform temperature of nitrification and denitrification is between 25℃ and 30℃. When the temperature is lower than the transform temperature, the reduction of adsorption capability for ammonium nitrogen (N H₄⁺-N) is due to nitrification. And when the temperature is higher than the transform temperature, the reduction of adsorption capability for ammonium nitrogen (N H₄⁺-N) is due to denitrification.