Carbonation is the key factor that causes the corrosion of the reinforcing steel embedded in concrete. The surface layers of the concrete specimens were treated by superabsorbent resin（SAR）synthesized in situ， i.e.， the concrete surface was impregnated by the precursor solution of poly（acrylic acidcoacrylamide）with initiator and crosslinker， and then the impregnated concrete was radiated by infrared ray to synthesize SAR in situ. The resistance to carbonation was studied for the concrete treated with SAR in comparison with the hydrophobic waterproofing agent of alkylalkoxyl silane（AAS）. The carbonation depth of concrete after the accelerated carbonation testing was measured and the ingress of carbon dioxide was evaluated quantitatively by the sophisticated technique of Xray diffraction（XRD）. The results show that the concrete specimens treated with SAR have higher resistance to carbonation than that of the concrete specimens treated with AAS and the control concrete specimens.