Abstract: In order to obtain the optimal fertilizer combination of Hetao irrigation area and reduce the environmentalcontamination caused by the nitrogen leaching, slow controlled release fertilizer （HK）, granular organic fertilizer（F）,microbial fertilizer （W） and farmer accustomed fertilization （CK） had been set up as four fertilization treatments to discussthe impact of different tertilization combination on the content of NO3--N and NH4＋-N in soil leaching solution in Hetaoirrigation area. The results showed that the content of NO3--N and NH4＋-N decreased as the soil depth increased and underthe different treatments NH4＋-N can be controlled efficiently. Microbial fertilizer （W） was able to weaken the process of thetranslation from nutrition to NH4＋-N and the ammonification of the soil and theretbre the volatilization of the ammonia in thesoil was reduced.