Abstract:A pot experiment conducted to investigate the nitrification of different nitrogen fertilizers in soil, the effect of chlorine of ammonium chloride on restraining nitrification under planting maize and without crop conditions and its influence on the nutrition and growth of maize. The results indicated that the order of nitrification for different nitrogen fertilizers was urea>ammonium sulfate>ammonium chloride. The nitrification was decreased when the urea or ammonium sulfate was combined with ammonium chloride. There was a marked negative correlation between the nitrification and the content of chlorine in soil. The chlorine of ammonium chloride could restrain the nitrification but its influence on restraining nitrification was related to the variety of nitrogenous fertilizers and the growth of crop. The effect of chlorine on restraining nitrification was stronger for urea than for ammonium sulfate, and as same as dicyandiamide. The nitrification of nitrogen in soil was promoted when the maize was planted, and the effect of chlorine on restraining nitrification decreased with maize growing and chlorine absorbed. The seedling of maize grew poorly when the nitrification was stronger or weaker. In this experiment, the suitable ratio of maize absorbed NH4+-N and NO3--N was 1∶0 7～1 0, the ratio of NH4+-N and NO3--N could be adjusted in soil and the biomass yield of maize increased when the ammonium chloride was applied rationally.