Amine grafted mesoporous materials such as MCM-41, etc. have been approved as a type of good candidates for CO2 capture by many experimental results. However, the theoretical or molecular simulation studies about the effects of the grafted amine groups on the CO2 adsorption are far from sufficient to deeply understand the adsorption mechanism. The difficulty lies in the fact that it is hard to formulate a precise interaction between CO2 and amine group. In this work, CO2 adsorption in the amine grafted mesoporous material was simulated by grand canonical Monte Carlo (GCMC) method. Enhanced physical interaction was used to describe the weak chemical interaction between CO2 and amine group. The effects of the density of grafted amine groups on properties of the mesoporous materials, the adsorption quantity, as well as the adsorption selectivity were investigated. The simulation results were quite comparable to the real experimental ones. (C) 2012 Elsevier B.V. All rights reserved.