The biochemical composition of highbush blueberry fruit of 6 cultivars with different ripening periods, introduced in Belarus, is investigated on 14 indicators thrice a month at equal intervals. The nutrient and vitamin value of the fruit gradually decreased with the increasing amount of the dry matter, during storage, due to the depletion of free organic, ascorbic and phenol carboxylic acids, soluble sugars, pectic substances, tanning agents, anthocyanin pigments, catechins and flavonols. The transformation of the biochemical composition of the fruit, during storage, is strongly dependent on weather conditions of the season, rather than on their ripening period.