The influence of the aspect ratio to the light-scattering properties of small size cylinder ice particles in cirrus cloud is studied by T-matrix method. The light-scattering characteristic quantities such as the phase function, extinction efficiency, asymmetrical parameter and single-scattering albedo are computed.The results are compared with those of the equivalent sphere with the equal surface-area, the equal volume and the equal volume-to-surface-area ratio. It is found that properties with respect to the same volume-to-surface-area ratio are mostly close to the reality. The influence of the aspect ratio on light scattering properties of cylinder particles with different size parameters has similarity and should be considered. In addition, there is a nodical point in the phase functions of cylinder particles with the same surface areas but different aspect ratios.