The vertical concentration distribution of lower-troposphere (2 km below) atmospheric CO2 in Hefei western suburb is measured by Raman lidar system. By system calibration and moving average of the data, the vertical concentration profiles of atmospheric CO2 are retrieved. Through statistical analysis of the retrieved results of lidar observation data from July 2014 to December 2015, the variation patterns of lower-troposphere atmospheric CO2 vertical concentration distribution in Hefei western suburb are initially obtained. The results show that the CO2 vertical concentration distribution of lower-troposphere decreases with the increase of altitude, the concentration is rather high and changes intensely under near-surface 150 m, but the concentration of atmospheric CO2 above 300 m is getting stable. The lower-troposphere CO2 vertical concentration distribution shows obvious connection with the season, with a minimum in summer and a maximum in winter. The lower-troposphere atmospheric CO2 vertical distribution shows some correlation with the month, and the whole CO2 vertical concentration goes up with a rate of about 2×10-6 per year. Through the experiments, it is found that the CO2 vertical concentration shows a non-monotonical decrease with the altitude increase. There exists a CO2-rich area from 300 m to 700 m, and the CO2 concentration of this area decreases as the sky turns bright.