A prototype Raman lidar was designed for monitoring tropospheric CO2 profile and other scientific investigations. The third harmonic of Nd:YAG laser (354.7-nm wavelength) was used as stimulated light source to provide nighttime measurements. Filter with high rejection ratio performance was used to extract CO2 Raman signals from Rayleigh-Mie scattering signals effectively. To improve the real time monitoring function, a two-channel signal collection system was designed to collect CO2 and N2 Raman scattering signals simultaneously. The N2 Raman scattering signals were used to retrieve aerosol extinction coefficient. Typical features of CO2 concentration profile and aerosol extinction coefficient in Hefei were presented. The mixing ratio of atmospheric CO2 in Hefei can reach about 360-400 ppmv.