Based on the residual urea variance rate as evaluating indicator,the factors that affect the inhibiting efficiency evaluation of urease inhibitor were studied,which including:extraction temperature,extraction duration,urease solution concentration,soil dosage,extract types and etc.A rapid detection method was established for evaluating the efficiency of urease inhibitor in stabilized urea:1.000 0 g of ordinary urea was taken as the controlled fertilizer,1.000 0 g of stabilized urea and 10 g of dried soil were weighed,and then 100 mL of 0.5 g/L urease buffer solution was added,and then the amount of urea residual in soil after 5 hours oscillation at 37℃ was measured.The detection method increased the evaluating efficiency and accuracy.