Carbonation process of calcium-based sorbent, as a promising technique for CO, capture, was examined in a fixed-bed reactor. A method was established to calculate the exact adsorption capacity using CO2, Non-Dispersive Infrared Radiation (NDIR) analyzer as the analytical unit. The factors affecting the carbonation process of calcium-based sorbent were investigated thoroughly. The conversion and adsorption capacity of sorbent reached 6596 and 4196, respectively, when CO2, partial pressure was 0.01 MPa at 600 degrees C, exhibiting an obvious advantage in terms of a relatively low carbonation temperature. The results showed a first-order reaction with respect to CO2 partial pressure. Increasing carbonation pressure was an effective method to improve adsorption capacity, and conversion and adsorption capacity of sorbent achieved 8596 and 5396 at 1.3 MPa, respectively. The existence of water was beneficial to the carbonation process and the influence can be explained by the process of water hydration of CaO. The Random Pore Model (RPM) was applied to describe the carbonation process in the reaction-controlled stage and the predicted data obtained from the model showed good accordance with the experimental results.