Abstract: 【Objectives】The impacts of nitrate inhibitor (dicyandiamide, DCD)on crop yields and residuals of soil nitrate N in field have been less reported under field condition. It is of great importance to research its effects in different nitrogen (N) fertilization modes for high maize yield, low N2O emission and high fertilizer-nitrogen use efficiency.【Methods】A field experiment was conducted in the Changwu State Key Agro-Ecological Station from April 2013 to September 2014. Pioneer 335, a high-yield spring maize hybrid, was chosen and planted with half plastic film mulching. The experiment consisted of 4 N fertilization treatments with three replicates: conventional N fertilization rate (Con), optimal N fertilization (Opt), optimal N fertilization plus nitrification inhibitor (Opt+DCD) and control treatment (N0). Soil samples and N2O were gathered at regular intervals, soil mineral N and N2O were analyzed using continuous flow analyzer and gas chromatograph 【Results】The Opt and Opt+DCD treatments can maintained the maize yields, and simultaneously significantly influence the N2O emission and the residuals of nitrate nitrogen. The peak values of nitrate nitrogen are significantly decreased by 13.7% and 19.0% in the Opt and Opt+DCD treatments, respectively. The nitrogen application modes also affect the time of peak values. The peak values of nitrate nitrogen are appeared in the Con treatment (190.1 mg/kg) firstly, and then the Opt (164.0 mg/kg) and Opt+DCD (132.9 mg/kg). The N2O emission is significantly decreased in the Opt treatment (29.4%), whereas further decreased (28.1%) in the Opt+DCD treatment. The nitrate concentration is fluctuated with precipitation during rainy season. The peak value of ammonium nitrogen is increased in the Opt+DCD treatment, although it is decreased in the Opt treatment. The residuals of nitrate nitrogen at the depth of 0-100 cm and 100-200 cm of four nitrogen application modes are in the ranges of 33.5-148.9 kg/hm2 and 24.8-92.8 kg/hm2, with mean values of 78.5 mg/kg and 56.4 kg/hm2, respectively. The highest accumulation of nitrate nitrogen in profile (0-200 cm) is in the Con treatment (225.9 kg/hm2), and about 48.0%-59.0% and 29.4%-57.5% of the accumulation are decreased in the Opt and Opt+DCD treatments compare to that in the Con treatment, respectively. The residuals of nitrate nitrogen between Opt and Opt+DCD have not significant difference. 【Conclusions】Different N fertilization modes have significant impact on maize yields, dynamics of soil mineral N and N2O emissions and agronomic efficiency of fertilizer-nitrogen. However, with the N application rate reduced by 20%, the treatments of Opt and Opt+DCD not only maintain the maize yields, but also further decrease the residuals of nitrate nitrogen in soil profile and emissions of greenhouse gas from agricultural sources. Therefore, DCD addition is a kind of scientific and effective fertilization management mode in rain-fed agricultural region of Loess Plateau.