Introduction: Genus of Artemisia L. is one of the largest (Asteraceae). There are about 84 species in Siberian flora [1]. Artemisia absinthium L. and Artemisia vulgarisL. are mostly used in medical practice. A.vulgaris L. is widely spread in Buryatia as a weed plant and A.absinthium L.grows only in Kabansky district. One of the Absinthium DC section is A. Sieversiana Willd. which also grows in Buryatia. It is known that pharmacological activities of genus Artemisia plants occur due to the essential oils and sesquiterpene lactones. Speaking from the perspective of efficient use of medical plant materials, it is interesting to explore another group of biologically active substances, including flavonoids.The main aim of this work is to identify the presence offlavonoids, and make chemical assay of them in HerbaA. absinthii и A. Sieversianae. To achieve this goal we should make the following tasks: 1) to reveal main anatomical diagnostic features of Herba A. absinthii andA. Sieversianae; 2) to make phytochemical analysis;3) to identify the presence of flavonoids using thin layer chromatography (TLC); 4) to make quantitative determination of flavonoids by spectrophotometry.As a plant material in this research we used Herba A. Sieversianae which was collected in the Republic of Buryatia (Ivolginsky district), in Tomsky region (suburbs of Tomsk) and in Mongolia (suburbs of Ulan-Bator) in 2011-2012 during the flowering period; and HerbaA. absinthii of “Health” Firm manufacturing. To make these tasks we used the next methods: 1) microscopic analysis for revealing main anatomical diagnostic features; 2) phytochemical analysis for identification of biologically active substances; 3) TLC to identify the presence of flavonoids; 4) spectrophotometry for quantitative determination.We made microscopic analysis according to the established article “Technique of microscopic analysis” [2]. The main anatomical diagnostic features of HerbaA. absinthii are flaxuose walls on upper epidermis,anamocytic stomata, numerous T-shaped fuzzes;on both surfaces of epidermis there are large oval trichomes with essential-oi [2]. For HerbaA. Sieversiana they are: cells with curving walls on epidermis; narrow elongate stomata; specific T-shaped fuzzes; it is seen the places of fuzzes’ fixture on epidermis and large trichomes with essential-oil [3]. The identification of flavonoids was made by TLC plates “Sorbfil” with aluminium substrates in solvent system chloroform – ethanol – water (26:14:3) using standard technique [4]. Then these chromatograms should be faced with ammonia gas. There are spots of rutin which coloured into dark-brown in UV spectrum (Rf 0,73). We identified essential oils, flavonoids, coumarins and polysaccharides using standard identity tests [5]. And quantitative content of flavonoids calculated as rutin was determined by spectrophotometry (λ=410 nm), and the results: in plant raw material from “Health” Firm manufacturing – 0,03%, raw material which was collected in the Republic of Buryatia – 0,85%, in Tomsky region – 0,39% and in Mongolia – 0,52%. For making extract we used 70% ethanol (proportion of raw material and extraction fluid 1:20) [6].In general, we identified the main anatomical diagnostic features of Herba A. absinthii and A. Sieversianae, made phytochemical analysis and quantitative determination of the sum of flavonoids calculated as rutin.References:1. Krasnoborov I.M. The flora of Sibiria. – Novosibirsk:Nauka, 1992.2. State Pharmacopoeia of the USSR. Ed. XI (part 2). Common methods of analysis. Medical plant material / USSR Ministry of Health. - 11th ed., Ext.– M.: Medicine, 1990. - 400 p.3. Bereznegovskaya L.N., Serih E.A. Some pharmacognostic issues about wild and cultivated plants in Sibiria. – Tomsk: Publishing center of Tomsk State University, 1969.