Since 1970, global warming has been an issue followed by weather change due to rapid industrial developments in many area and IPCC(Intergovernmental Panel on Climate Change) has been effecting agricultural aspects in many ways. Acquiring emission coefficients and evaluate emission levels that fit to domestic agricultural environment is needed to be adapted to the environmental weather changes due to greenhouse gas. We have been evaluating N2O emission as levels of nitrogen fertilizer during soybean cultivation in flat upland since 2009. N2O emission was measured in chemical nitrogen fertilizer amounts 0(N 0), 16(N 0.5), 32(N 1.0), 64(N 2.0) kg ha-1 by using the abnormal shape chamber closed  repeating three times. All experiments were performed during soybean cultivation in flat upland. Emission levels were measured by changing of N2O concentrations in chamber during 30 minutes from AM 10:00 to AM 10:30 twice a week. The data was analyzed by Gas Chromatography (Varian 3800 GC/ECD detector), and the temperature differences within the camber, ground temperature, soil water content, soil chemical properties, and weather data was also monitored. In 2011, the total N2O emissions of each treatment in field of soybean were 0.761(N 0), 1.085(N 0.5), 1.493(N 1.0), and 1.856(N 2.0) kg N2O ha-1 yr-1, respectively. And then the primary regression between nitrogen fertilizer amount and the total N2O emission was showed as y = 0.0172x + 0.818 (r2=0.9667), and an average of the default value was EF1 0.0223(0.0190～0.0254) N2O-N kg N-1 kg-1 in 2011. These results were higher about 2 times than the default value of the IPCC 2006 guideline(EF1 0.01) when the results are converted into emission defaults. Conclusively, we expect that this study can be applied to acquire emission default and evaluate N2O emission, which are appropriate for the different field crops in domestic agricultural environment.