Introduction. Among the different groups of drugs, diuretics are one the most popular classes that have been used for treatment of cardiovascular system and kidney diseases. At the same time, synthetic diuretics which are widely used, cause large amounts of side effects, such as violation of electrolyte, acid-base and water balances, carbohydrate and lipid metabolism. Therefore, it is important to search for individual compounds of plant origin – potential pharmaceutical substances for the treatment of urinary tract diseases. In this study individual compounds were isolated from the terrestrial parts of Ononis arvensis L. and Solidago canadensis L. The diuretic activity of the summary extracts of Ononis arvensis and Solidago canadensis has previously been proven. Aim. Method development for the isolation of individual compounds, using modern physicochemical methods of analysis, from the terrestrial parts of Ononis arvensis and Solidago canadensis and the elucidation of their structure. Materials and methods. Aerial parts of Ononis arvensis and Solidago canadensis were collected in the Saint Petersburg State Chemical-Pharmaceutical University (SPCPU) Nursery Garden of Medicinal Plants (Leningrad region, Vsevolozhsky district, Priozersk highway, 38 km) in August 2019 and identified by Dr. Goncharov Mikhail of the Saint-Petersburg chemical-pharmaceutical university, Saint-Petersburg, Russia. Fraction analysis were preformed with analytical high-performance liquid chromatography using a LC-20 Prominence (Shimadzu corp., Japan) with a SPD-M20A diode-array detector. Isolation of individual compounds was carried out by preparative high-performance liquid chromatography using a Smartline (Knauer, Germany). The structures of the isolated compounds were elucidated using 1D and 2D NMR experiments (Bruker Avance III 400 MHz) along with HR-ESI-MS (Bruker Micromass Q-TOF). Results and discussion. Using the developed methods, from the aerial part of the field restharrow (O. arvensis) we managed to isolate and characterised three individual compounds (1-3). Compounds 1 and 2 are isloflavonoids – pseudobaptigenin-7-О-ß-D-glucopyranoside and formononetin-7-О-ß-D-glucopyranoside, respectively. Compound (3) is a flavonoid – kaempferol-3-O-ß-D-glucopyranoside (astragalin). All compounds were isolated for O. arvansis for the first time. Along with this, four individual compounds (4-7) were isolated from the aerial part of the canadian goldenrod (S. canadensis), namely, quercetin-3-O-ß-D-6''-acetylglucopyranoside, isoramnetin-3-О-ß-D-rutinoside (narcissin), quercetin-3-О-rutinoside (rutin) and quercetin, respectively. Conclusion. As a result of the research, methods have been developed for the isolation of 7 individual compounds, using modern physicochemical methods of analysis, from the aerial parts of Ononis arvensis and Solidago canadensis, the structures of all the isolated compounds were elucidated. Future assessment of the isolated compounds biological activity is presumed.