Based on the one dimensional line by line radiation transfer model (LBLRTM) and the concentration model of CO₂,the greenhouse effect saturation of CO₂ was analyzed and the coming surface temperature rise was predicted.The results show that so far as we know,the continuous emission of CO₂ has just brought about the absorption saturation at the center of the 680 cm^-1 strong absorption band,while the wing areas of the band and the weak absorption bands such as 1 000 cm^-1,1 350 cm^-1and 1 900 cm^-1are far from saturation,therefore,CO₂ still has a strong greenhouse effect during quite a long time in the future.If the emission rate of CO₂ basically remains at the current level 2.2 (mL·m^-3)/a,its atmospheric concentration would increase continuously,which would result in a surface temperature rise of 2 K by 2056.