Novel carbonized polydopamine adsorbents (C-PDAs) with high surface area, high CO2 adsorption capacity and superior moisture resistance performance were prepared by one-step synthesis method using polydopamine as carbon precursor at different KOH/C ratios, and then characterized. CO2 and water vapor adsorption performances of C-PDAs were examined separately by static adsorption and fixed-bed experiments. Results showed that BET area and pore volume of C-PDA-4 were up to 3342 m(2)/g and 2.01 cm(3)/g, respectively. Its CO2 adsorption capacity reached up to 30.5 mmol/g at 25 bar, much higher than many other adsorbents including metal-organic frameworks (MOFs). C-PDAs prepared with high KOH/C ratios had low surface element concentrations of O and N resulting in low surface hydrophilic property. H2O(g) isotherm of C-PDA was much lower than those on Mg-MOF-74, Cu-BTC, and MIL-101(Cr). Fixed-bed experiments showed that co-presence of water vapor in feed stream with 30% RH had negligible impact on CO2 working capacity of C-PDA. (C) 2016 American Institute of Chemical Engineers AIChE J, 62: 3730-3738, 2016-