EN
Qualitative and quantitative analysis of phenolic acids and flavonoids was made in Fraxinus excelsior L. leaves. The presence of caffeic acid, rutin and quercetin-3-rhamnoside was confirmed. Moreover, it was identified quercetin and following phenolic acids: protocatechuic, p-hydroxybenzoic, vanillic, syringic, sinapic, ferulic and p-coumaric. It was ascertained that flavonoids content in F. excelsior leaves (0.13%) is lower than phenolic acids content (0,30%) and depend on the time of raw material harvest.