An investigation of snow characteristics in Alpine environment was carried out using COSMO-SkyMed and Landsat-8 images. After a check of the X band SAR data, together with simultaneous optical images in separating snow/no-snow areas and in detecting wet snow, the sensitivity of backscattering to snow depth was explored. A model based on Dense Media Radiative Transfer theory (DMRT-QMS) was applied for simulating the backscattering response at X band from snow cover in different conditions of grain size, snow density and depth. By using the model and snow data collected on the Cordevole basin in Italian Alps, the effect of grain size and snow density was pointed out, showing that the snow features affect the backscatter in different and sometimes opposite ways. Experimental values of backscattering were correctly simulated by using this model providing a relationship between simulated and measured backscattering with slope >0.9, determination coefficient, R 2 = 0.77, and root mean square error, RMSE = 1.1 dB.