Abstract: From a universal formula for calculating the attenuation cross section of particles in arbitrary shapes, exact expressions for calcualting the at tenuation cross section of poly-disperse, small spheroids, whose rotary axes are in specific status, have been derived. Attenuation crosssections of both liquid and ice particles in different shapes at different wavelengths in microwave band have been computed and analyzed. The results are infor-mative to microwave remote sensing of precipitation.