In this paper,based on the theory of electromagnetic scattering,the expressions for scattering features of a small spheroidal particle incident by polarized waves from a bistatic polarization radar system have been established and the physical concept and distribution patterns at different incident angles have been discussed.The results provide a theoretical basis for inference of spheroidal raindrop-based bistatic polarization radar detecting equations,as well as the study on the impact of spheroidal raindrop on the detection capability of bistatic polarization radar,and even the data processing and analysis of bistatic polarization radar detecting system.