Quantitative characteristic of biological productivity for most waterlogged region of Western Siberia, Surgut Polesie, is presented in the paper. The field work was carried out in two sites presented oligotrophic (ombrotrophic) mires: Tor and Federovskoe. Both sites included upland (ridges, and raised bog with pine - ryams) and lowland (hollows) mire ecosystems. Sphagnum fuscum-dwarf shrubs-pine plant community was in the ridges and the ryam and sphagna- sedge or sphagna-cotton grass community - in the hollows. Values of net primary production in oligotrophic ecosystems of Surgut Polesie were similar and sufficiently high and reached 530-630 g∙m-2∙year-1 depending on the topography and location of mires and does not depend on the value of living phytomass. In contrast to net primary production, value of total phytomass was significantly higher in upland mire ecosystems than in lowland ones: 2500-3500 g∙m-2 in the ridges and the ryam and 1010-1250 g∙m-2 in the hollows. The contribution of trees on upland elements of microrelief was from 30% to 40% of total living phytomass and 11-16% of net primary production of mire ecosystems. In above-ground sphere the main contribution in net primary production belongs to mosses in the all ecosystems as well as foliage of dwarf shrubs in the upland ecosystems, in below-ground sphere - roots of dwarf shrubs, trees and grass, and rhizomes of grass. In above-ground sphere the greatest phytomass value was obtained for perennial wooden parts of trees in upland ecosystems and for mosses in hollows, in below-ground sphere - for all plant fractions in upland ecosystems and for roots and rhizomes of grass in lowland ecosystems.