It were cultivated the buckwheat (Fagopyrum esculentum Moench.) seeds of sort Pyra of Middle Europe origin (Czech Republic) in Azerbaijan condition and the flavonoid composition of their aboveground parts were studied. By the chromatographic method determined that polyphenol complex of the aboveground part contains flavonols, anthocyanins and phenol-carbon acids. 5 individual flavonoids by chromatographic methods were obtained. Flavonoids were identified as quercetin, kaempferol, rutin, quercetrin and astragalin by physical, chemical and spectral methods. The last flavonoid was firstly determined in buckwheat. Anthocyanin was identified as cyanidin-3,5-diglycoside. It was found that the main components of the aboveground part of buckwheat are rutin and quercetrin.