Radon exhalation and radioactive background were investigated in the region of the natural growing of the Karelian birch, and also in the zone of mass woody anomalies. Background radiation was measured by means of the СРП-68 sсintillation searching radiometer. The coordinates of measuring points were fixed through GPS navigator. Measured by means of the СИРАД М106 N radon indicator, the bulk radon activity at the roots of the Karelian birch was 111 Bk/m3, in the zone of mass woody anomalies – 60 Bk/m3, that considerably exceeded base-line values in safety zones. Relationship between radon exhalation and appearance of structural anomalies in woody plants in the zones of radon danger has been discussed.