Adsorption is a plausible technology using solid adsorbents for dry capture of carbon dioxide (CO2). In general, narrow size distribution of tiny pores and surface chemical functionalities of solid adsorbents enhance the adsorption capacity of gaseous CO2 molecules. In order to utilize the advantages of fibrous adsorbents, this work prepared activated carbon nanofibers (ACNFs) via the electrospinning process using a polymer precursor of polyacylonitrile (PAN). The spun fibers were 390 nm to 580 nm in thickness with an average surface area of 27.3 m(2)/g. The surface structure was improved by a programmed thermal activation at 800 degrees C in CO2 atmosphere. It was also found that the nitrogen-groups including pyrrole and pyridine were created during the activation facilitaing the selective adsorption as forming enhanced active sites. The finally obtained adsorption capacities were 2.74 mmol/g for pure CO2 flow and 0.74 mmol/g for 3000 ppm.