Oxygen chemisorption on a porous coal char was investigated by a typical consecutive pyrolysis and chemisorption experiments in a thermogravimetic analyzer. Small amounts of carbon-oxygen surface complexes are gasified to CO and CO2 during the oxygen chemisorption at 423 K. The kinetic equation of oxygen chemisorption on porous char including gasification of surface oxides well represents the chemisorption/gasification behavior of oxygen on the coal char. The activation energy and the frequency factor for oxygen chemisorption on coal-char are found to be 57 kJ/mol and 9.16x10(6)/hr, respectively.