Abstract: Raman scattering lidar is an important technique, which has the high space-time resolution, can measure atmospheric carbon dioxide mixture ratio profiles in real time. It is based on the Raman scattering frequency shift caused by laser and atmospheric CO2 or N2 interaction. A Raman scattering lidar system developed by Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, was introduced. And the theory and method for atmospheric CO2 space-time measurement were expatiated on. Two CO2 analyzers prior calibrated by each other, which tested the lidar's results reliability, were placed in the sites of transmitting terminal and one kilometer distance along the laser path. Experiment results displayed the two analyzers have good consistency with the lidar's in near-end and far-end respectively, where there are 0.8 ppm and 3.51 ppm difference in whole night averaged values. It was explained that the difference of CO2 mixture ratio in near-end and far-end. Thus atmospheric CO2 profiles monitored by Raman scattering lidar have authenticity and reliability.