Plants of the genus Peucedanum attract the attention of researchers as sources of coumarins. We isolated previously from P. terebinthaceum Fischer et Turcz. of Mongolia flora the pyranocoumarin (+)-pteryxin [1]. Plants of the species Ferulopsis hystrix Bunge (P. hystrix) were characterized as sources of angular furocoumarins [2]. The species P. baicalense (Redow.) Koch is broadly distributed over Mongolia [3]. Peucedanin, imperatorin, isoimperatorin, fellopterin, deltoin, bergapten, and 8-hydroxy-5-methoxypsoralen were previously isolated from its roots [3]. We studied compounds extracted from P. baicalense collected in Baruunburen, Selenge Province, Mongolia, during budding-flowering. The concentrated EtOH extract of subterranean organs was diluted with H2O. Coumarins were extracted sequentially by hexane (1.15% yield), Et2O (0.33%), and EtOAc (2.28%). An analysis of PMR spectra of the fractions showed that the principal components of the hexane extract were diacetylene compounds, coumarins (~30%), and sterols (~12%). Extracted compounds were separated by column chromatography over silica gel. Chromatography of the hexane extract (2.4 g) isolated sequentially the diacetylene alcohol falcarinol (1) and pure linear furocoumarins isoimperatorin (2) (0.032% of raw material weight), fellopterin (3) (0.038%), and 8-(1,1-dimethylallyloxy)bergapten (4) (0.044%).