This paper demonstrates the capability of SIR-C/X-SAR in mapping seasonal snow cover in an alpine region. The polarization properties at each frequency, the ratios from different frequencies and the synthesized polarization measurements are little affected by topography. Through evaluated angular dependence and separabilities of each target within the scenes, the authors can determine the optimal measurement set for classification performance. In contrast to a single polarization SAR, SIR-C/X-SAR has capability to map both dry and wet snow covers and suitable for large scale snow mapping.