This letter proposes relationships between boreal forest microwave transmissivity and four forest structural parameters: summer and winter Leaf Area Index (LAI) from MODIS, biomass (t ha^-1), and total volume (m³ ha^-1) for northern Québec, Canada. These relationships were derived for summer AMSR-E data sets that took into account the effects of canopy emission and scattering. Root mean square error results between brightness temperature simulations and ASMR-E observations are approximately 5 K. Results reported in this study can be used as forest correction equations for key surface parameter retrievals under the boreal forest canopy, such as soil moisture or snow depth/water equivalent.