The fatty acid composition of lipids from mature pollen of the main representatives of genus Betula L. growing in southern Karelia was investigated for the first time. It is shown that in the spring season pollen cells contained high amounts of lipids, represented both by storage (neutral) lipids (43 %) and membrane (phosphor- – 24 % and glycol- – 33 %) lipids. The main fatty acids of the microgametophyte were the palmitic among saturated acids, and the linoleic and linolenic among unsaturated acids, but their amount varied depending on the lipid fraction. In the neutral fraction and phospholipids there accumulated primarily di=and triene fatty acids, whereas in glycolipids their share was somewhat lower as significant amounts of monoene fatty acids (mainly oleiс) were present. In all probability, this fact is connected with the physiological characteristics of a mature microgametophyte realized at the cellular level.