The areal snow dept and snow water equivalent have been investigated with some success using passive microwave data. The amount of snow accumulated determines the runoff after the onset of melt during spring. Hence, the measurements of snow cover characteristics are very important. The retrieval accuracy however, has not been well determined for heterogeneous vegetated regions. The sensitivity analysis of the forest on the brightness temperature of snow emission model using Special Sensor Microwave Imager (SSM/I) frequencies are investigated. The sensitivity analysis was performed for two different brightness temperature functions, each involving four frequencies dual polarisations. The parameters of interest were forest temperature and forest stem volume. At SSM/I frequencies the forest canopy and the snow-covered ground dominate the emissivity behaviour in the boreal forest zone. The principal objective of this study is to analyze the degree to which SSM/I brightness temperature can be affected by the forest parameters.