Atmospheric aerosol and cirrus clouds modulate the balance of the radiation budget between the earth and its atmosphere, through their direct, indirect effect and the reaction of each other. In order to study microphysical properties of atmospheric aerosol and physical properties of cirrus cloud, a three-wavelength-Raman-polarization lidar system is developed, which is composed of transmitter, receiver, control, and data acquisition subsystems. It has many advanced characteristics, such as multiply wavelengths, large detecting range, fine temporal and range resolution, good detection sensitivity and reliable data. The backscattering coefficients of 355, 532 and 1064 nm, extinction coefficients of 355 nm and 532 nm, and depolarization ratio of 532 nm can be retrieved from this lidar system. Case study indicates that the data acquired from this lidar are reliable and can be used for study of the microphysical properties of the aerosol and cirrus cloud.