Introduction: N-(N-butyl)thiophosphoric triamide is a kind of effective soil urease inhibitor, N-(N-butyl)thiophosphoric triamide as soil urease inhibitor, highly effective, non-toxic, the soil has no side effects, and the natural degradation of ammonium and phosphorus in the soil, can also be used as fertilizer absorbed by the crop root systems, and reduce the toxicity of ammonia on seed germination and seedling growth, it is a good soil urease inhibitors. Experiment and production practice shows that under the condition of non acidic soil, good ventilation, urease inhibitor NBPT in hydrolysis of urea enzyme inhibition (N-(N-butyl)thiophosphoric triamide) > PPD (phenyl phosphorus acyl diamine) > HO (hydroquinone), NBPT inhibition of NH3 volatilization in ventilation conditions are much better than PPD and HQ, and NH3 volatilization loss is reduced to 20% from 3%. When urea hydrolysis in the accumulation of nitrite and nitrite and nitrate ions mobility strong are prone to leaching, but when NBPT is added in the urea, its dosage is just 10 ug/g soil, nitrite accumulation can be reduced from 11% to 11%. Without adding organic material in soil, NBPT still can make into urea N fixed by 30%. Urea added NBPT applied in farmland, to improve seedling germination, to promote plant absorption of "n" in the soil and increase crop yields have obvious effect. At present the United States, Canada, Australia, Brazil and so on food production country of large chemical fertilizer company has to large-scale industrial development of NBPT, its preparation add NBPT long-effect urea has been widely applied to agriculture.