Ectomycorrhizae play important role in functioning of forest ecosystems where they are also one of the major carbon sinks. Physiological activity of vital cells in ectomycorrhizae was studied by using fluorescein diacetate (FDA) and fluorescence microscopy. Fluorescence activity of ectomycorrhizal mantels depends on physiological state of trees and species composition of fungi. Ectomycorrhizal root tips of Siberian spruce (Picea obovata) and Scotch pine (Pinus sylvestris) were sampled in different boreal forest sites in European part of Russia (the Komi Republic) during one growing season. Tissue fluorescence activity was estimated for nine ectomycorrhizal types of Scotch pine and for seven ectomycorrhizal types of Siberian spruce. Certain differences occurred among ectomycorrhizal types in FDA-hydrolysing activity of the different tissue layers of mycorrhizae: cortex, hyphal mantel, Hartig net and stele. All main tissues of coniferous ectomycorrhizae with plectenchimatous mantels of type A were characterized by higher fluorescence activity. Fluorescence intensity of fungal mantels in ectomycorrhizae of types В-, Е-, F-, G- and N was lower, but their stele indicated intermediate activity. Low activity of all tissues except for stele was registered in ectomycorrhizae of O-, Q- and RS-types, so these types were classified as inactive ectomycorrhizae. Highest fluorescence of ectomycorrhizae was recorded in period of their maximum growth in seasonal dynamics. Insignificant quantity of ectomycorrhizae with low activity was found during all the observation season.