Ordered nitrogen-doped mesoporous carbon CO2 adsorbents were synthesized by a simple one-step hydrothermal self-assembly method using F127 as a soft template, melamine and urea as the nitrogen source without additional pre-polymerization steps. Characterization methods including N2 adsorption/desorption, XRD, TEM, FT-IR and XPS were taken to study the structure and surface properties of the adsorbents. Besides, the adsorption isotherms of CO2 and N2 on the ordered nitrogen-doped mesoporous carbon at different temperatures were determined, and the results were fitted and analyzed by various adsorption isotherm models (Langmuir, Freundlich, Temkin, Dual-site Langmuir (DSL) models), further combined with the IAST model, the CO2/N2 adsorption selectivity of adsorbents in simulated flue gas was predicted. The results indicate that the ordered nitrogen-doped mesoporous carbon exhibit large specific surface area (up to 498.6 m2/g), highly ordered mesostructure (P6mm space group) and high nitrogen content, and the nitrogen is uniformly doped in the carbon framework in various forms. It was found that the adsorption isotherms of CO2 and N2 on ordered nitrogen-doped mesoporous carbon were highly consistent with the DSL model. Moreover, NOMC-M with higher nitrogen content exhibit higher CO2 adsorption capacity (0 ℃, 3.55 mmol/g; 25 ℃, 2.67 mmol/g) and CO2/N2 adsorption selectivity(>40), and can still maintain good regeneration stability after continuous CO2 adsorption/desorption cycle test.