Abstract: Absorption and desorption of NH4+ by natural zeolite and modified zeolite is studied.Compared with natural zeolite, K – zeolite、Ca – zeolite、Mg-zeolite and Ba-zeolite to the NH4+ is stronger absorption and desorption capacity,and K – zeolite is the greatest. To H-zeolite, low concentration is higher than the natural adsorptive(desorptive) capacity,but high concentration is lower then the natural adsorptive(desorptive). The modified zeolite not only may enhance the adsorption of NH4+, but also may promoted the desorption of NH4+. It shows that modified zeolite not only has strongly guarantees the nitrogen ability, but also high nitrogen supplying ability. So it has broad application prospect in the agricultural practice.