The aim of our study were qualitative and quantitative analyses of two polyphenolic acids: chlorogenic and gallic acids. These compounds were determined in two species of Rhodiola: R. kirilowii and R. rosea. After collecting plants, aqueous and hydroalcoholic extracts were prepared. In order to identify analysed polyphenolic compounds ultra performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS, Waters) was used. Gallic acid is commonly found in the roots of these plants. Aqueous extract in both species is a rich source of gallic acid. The UPLC-MS/MS studies allow to use this analytical method for determination of polyphenolic acids accordance with the requirements of ICH. Chromatographic method developed by our team is more precise then previously published.