The article is devoted to research of above-ground biomass of oak (Quercus robur L.) windbreaks. Described are the morphological, biological, ecological and forest meliorative properties of common oak growing in windbreaks. The dependence between the amount of biomass components and the main mensurational and meliorative indices such as protective height and openness in the crowns of windbreaks has been established. As a result, mathematic models for the assessment of both the above-ground components of a tree,the crown, and a windbreak, as a whole, have been developed. It is determined that the relative density of the trunk has less accuracy than openness in the crown in the assessment of the components of above-ground phytomass of a windbreak. For a separate tree of 36 cm in diameter at breath height, 24 m in height, a 0.8 windbreak density and a 10 % openness of crown in windbreak, the share of trunk biomass is higher in a massive stand in comparison with a windbreak. However, the crown biomass in a windbreak is 6% larger than in a massive stand. The standards for determination of the amount of phytomass components for trunks and crowns of separate trees and oak windbreaks, as well as that of sequestered carbon have been developed. The developed models and standards were analyzed. and the structure of phytomass on the components and sequestered carbon done. The comparative analyze has revealed the trends towards increased share of crown phytomass in the oak windbreaks with increasing their biometric characteristics as compared to massive stands.