The plants of the genus Artemisia L. are rich in biologically active secondary metabolites. Phytochemical study of secondary metabolites of plants of the genus Artemisia has led to the creation on their basis, in particular, on the sesquiterpene lactones, antitumor (artemisinin and its derivatives; arglabin), antiatherosclerotic (leucomisin (preparation oligvon)), cardiotonic (tauremisin), anthelmintic (α-santonin) and antimalarial (artemisinin and its derivatives) preparations. This article is dedicated to the research of the chemical compounds of aerial parts A. marshalliana Spreng. The aerial parts of A. marshalliana collected for the first time in the vicinity of the Araz River in the Republic of Azerbaijan during the budding period, identified sesquiterpene lactone eudesmanolide structures. The study of the physicochemical properties of the obtained substance was carried out by spectral methods of UV, IR, 1H, 13C, 13C DEPT 135, 90, 45 NMR spectra and comparison of the results with scientific literature data. As a result, the elemental composition of the substance is С15Н18О3, m.p. 170-172°С which has been identified as α-santonin. The result can be used in obtaining the substance and its identification, as well as in chemotoxanomic classification of species of the genus Artemisia L.