A pot experiment was conducted to explore the effect of urease inhibitor n-propyl thiotriamine (NPPT)，nitrification inhibitor dicyandiamide (DCD)and their combinations on nitrogen form and maize yield in black soil，brown soil and cinnamon soil.Five treatments were set up，including without urea fertilizer(U0)，urea without inhibitors(U)，urea+ urease inhibitor (UN)，urea+ nitrification inhibitor (UD)，and urea+ urease inhibitor+ nitrification inhibitor (UND).The contents of urea nitrogen，ammonium nitrogen(NH4+-N) and nitrate nitrogen(NO^3--N) in soil were measured at seedling stage，big trumpet stage，grouting stage and maturity stage of corn，and the nitrification inhibition rate，nitrogen apparent use efficiency were calculated correspondingly. The area and chlorophyll content of the three leaves of the rod were measured at the initial stage of corn filling，and the biomass and nitrogen content of the corn were measured after harvest.Compared with U treatment，maize yield in black soil could be increased by inhibitor treatment，and UD yield increased by 1.5 times as much as that in U treatment，nitrogen apparent use efficiency increased by 2.12 times，and NH4+-N content in black soil significantly increased by 62.11%～121.21%.In brown soil，the yield increased significantly under UN and UD treatment，and UD treatment had the largest yield increase，which was 0.36 times higher than that under U treatment.Nitrogen apparent use efficiency increased by 2.79 times，and NH4+-N content in soil increased significantly by 43.13%～131.31%.Inhibitor treatment significantly increased the yield in cinnamon soil，and UND treatment increased the yield by 1.51 times as much as U treatment，nitrogen apparent use efficiency increased by 4.08 times，and NH4+-N content in soil increased by 19.08%～262.25%.DCD had a significant effect on the nitrification inhibition of urea nitrogen in black soil and brown soil. The high efficiency and stability urea fertilizer added with DCD should be selected in the black soil and brown soil planting corn.The combined application of NPPT and DCD had a good synergistic effect on the conversion of urea nitrogen in the cinnamon soil.The high efficiency and stability urea fertilizer added with the combination of NPPT and DCD should be selected for the corn planting in the cinnamon soil.