The construction of a graft copolymer is an effective method to modify the properties of CO2-based aliphatic polycarbonate (CO2-APC) for meeting specific needs. Herein, we describe a facile route for the synthesis of CO2-based APC-graft-polystyrene copolymers using a "grafting from" strategy. Firstly, the copolymerization of CO2 and epichlorohydrin (ECH) was performed for the synthesis of the APC of poly(CO2/ECH). Then, a functionalized-APC can be prepared by the substitution reaction of poly(CO2/ECH) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) that can serve as a precursor for the graft compolymer of P(CO2/ECH)-g-polystyrene via nitroxide-mediated radical polymerization (NMRP). The intermediates at each step and final graft copolymers were characterized using 1H NMR, GPC, DSC and TG analyses.