In this work, the adsorption behaviors of nickel oxide loaded activated carbons were studied in carbon dioxide capture. The nickel oxides were introduced onto the activated carbons using a post-oxidation method including nickel electroless plating at 573K in an air stream. The structure of the nickel oxide loaded activated carbons was characterized by XRD. The nickel oxide contents on the activated carbons were verified by XPS, and the textural properties were analyzed by N 2 /77K isotherms. The carbon dioxide adsorption behaviors of the nickel oxide loaded activated carbons were observed in the amounts of carbon dioxide adsorptions at 298K and 1.0atm. As the post-oxidation time increased, the carbon dioxide adsorption capacity was enhanced. From the results, it was found that the nickel oxide on the activated carbons led to an increase in the carbon dioxide adsorption capacity of the activated carbons.