The interest in using radar remote sensing for monitoring forest cover raises the following assets of radar data. The first is that radars can provide information related to the canopy volume, which cannot be collected by other means. The other advantage of radars is the possibility to acquire data over areas with frequent cloud or haze coverage. Besides their all-weather capability, it is demonstrated by experimental and theoretical studies that SAR (Synthetic Aperture Radar) systems have the potential to monitor vegetation moisture, biomass and morphology, and surface boundary conditions. The sensitivity of SAR backscatter to the vegetation volume varies with the frequency, polarization and the incidence angle at which the canopy is illuminated. Here comes the additional SAR advantage which is multi-frequency and multi-polarization capability of radar to identify vegetation types and to determine the vegetation parameters. By these, remote sensing using SAR has proved to be useful for many forest related applications and the use of SAR remote sensing for vegetation mapping has moved from the locally focused to the continental scale.