The global occurrence of cirrus clouds can reach as high as 30%, whose scattering properties are essential impact on the climatic model, radiative transfer, and remote sensing. Their scattering properties are determined by the ice crystal shape, size distribution, refractive index and so on. Retrieval of the backscattering color ratios of cirrus cloud using a 355, 532 and 1 064 nm three-wavelength lidar, combined with the simulation of the three backscattering color ratios of different ice crystal shape, the shape of the lidar-measured ice crystal can be estimated. The results indicate that the shape of cirrus cloud over Hefei city is mostly composed by aggregates.