Porous materials have always attracted high scientific interest because of their outstanding performance and potential applications in various fields, including adsorption and gas separation. Hyper-crosslinked polymers (HCLPs) have several advantages over other porous materials, they show extremely high surface areas and porosity, low density, outstanding adsorption properties, high chemical, and thermal stability.\nHerein, we reported a synthesis, characterization, and the CO2 (and other gases) adsorption performance of series of novel styrene-divinylbenzene based HCPs. The material was prepared in two steps. The first step involved the radical copolymerization of divinylbenzene (DVB) and 4-vinylbenzyl chloride (VBC), under solvothermal condition to generate porous polymers with high surface area above 700 m2 g−1. In the second step, various polyamine species were applied to react with the alkyl chloride groups and functionalize the pore surface\nto improve the CO2/N2, CO2/CH4 and CO2/H2 selectivity.