Generally, nitrogen (N) fertilization higher than the recommended dose is applied during vegetable cultivation to increase productivity. But higher N fertilization also increases the concentrations of nitrate ions and nitrous oxide in soil. In this experiment, the impact of N fertilization was studied on nitrous oxide (N2O) emission to standardize the optimum fertilization level for minimizing N2O emission as well as increasing crop productivity. Herein, we developed N2O emission inventory for upland soil region during red pepper and Chinese milk vetch cultivation.