Previous studies on the sea ice remote sensing based on microwave scatterometers mainly focus on distinguishing sea ice from sea water, and in turn, exploring the coverage of sea ice. The scatterometer onboard China-France Oceanography SATellite (CFOSAT), namely CSCAT, uses rotary fan beams to observe the earth surface, such that its multi-incidence and multi-azimuth observation geometry provides new opportunities for sea ice monitoring. In this study, the CSCAT backscattering coefficient data are firstly collocated with the sea ice concentration (SIC) data from European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and then the seasonal variations of the CSCAT backscattering coefficient under different SIC conditions in the Arctic and Antarctic are analyzed. Consequently, the spatial and temporal characteristics of the CSCAT backscattering coefficient over the sea ice zones are derived, which provide a foundation for developing a sea ice geophysical model function (GMF). The results show that the CSCAT backscattering coefficient increases with SIC. Under low SIC condition, the CSCAT backscattering coefficient shows good consistency in the Arctic and Antarctic, but there is an obvious modulation by wind speed, whose effect weakens as the SIC increases. In summary, the study provides relevant hints for the SIC retrieval using the scatterometer with fan-beam rotary scanning system.