Abstract: Ice cylinders are common in middle-latitude cirrostratus. Using wave theory for infinitely long cylinder irradiated by linearly polarized light, the intensity and polarization of scattering light by single ice cylinder are studied at different incident angles, size parameters and polarizations of incident light: (1) With increase of incident angle, intensity and polarization tend to be symmetrical and their numeric oscillation frequencies decrease. Intensity of scattering light totally weaken and changing degree of polarization increas; (2) With increase of size parameter, numeric oscillation frequencies of intensity and polarization increase, but amplitude of scattering intensity oscillation totally decrease; the number, intensity and location change when electric vector is parallel to in