Galeopsis bifida (Lamiaceae) and Phlomoides tuberosa (Lamiaceae) are broadly distributed over steppe and foreststeppe regions of the Selenga River basin [1]. Lamas in Buryatiya used G. bifida and P. tuberosa to treat diseases of the eyes and lungs and as sedative and antidiarrhea agents [2]. Chemical investigations found in G. bifida herb flavonoids, phenylpropanoids, iridoids, triterpenes, and lipids [3–5]; in P. tuberosa herb, phenolic acids, flavonoids, phenylpropanoids, neolignans, alkaloids, iridoids, and triterpenes [6–14]. Compositions of essential oils from the aerial parts of both species have not been reported. Herein we communicate results from a study of essential oils (EO) from leaves of G. bifida and P. tuberosa growing in Buryatiya. Raw material for the study (leaves of these plants) was collected in July 2008 near Atsagat (Buryatiya). EO was obtained by steam distillation in a Clevenger apparatus (steam-distillation time 2 h) and studied by GC/MS. The analysis was carried out using a 6890N GC/MS with a 5973N MS-quadrupole detector (all Agilent Techologies, EI ionization, ionization energy 70 eV, total ion peak recording, scan range 41–450 amu) and an HP-5MS capillary column (30 m 0.25 mm 0.50 m; stationary phase diphenyl- and dimethylpolysiloxane 5:95). The carrier gas was He, 1 mL/min flow rate. The injected sample volume (1% solution in hexane) was 0.2 L, stream division 20:1. The column temperature was 150–250°C (rate 2°C/min), vaporizer 250°C, ion source 230°C, detector 150°C, line connecting the GC to the MS 280°C. The mass spectra libraries NIST 05 and Wiley in addition to comparison of retention times with those of standards were used for identification. G. bifida. EO was waxy, yellow, weak aroma; yield 0.09% of air-dried raw material mass. A total of 24 compounds (21 identified, 84.6% of the total number) was detected. The dominant components were sesquiterpenes (77.8% identified). The highest contents were found for -caryophyllene (22.0%), spatulenol (12.1%), caryophyllene oxide (11.0%), and germacrene D (10.6%) (Table 1). The results were similar to those obtained earlier for EO of G. pubescens and G. tetrahit, the principal constituents of which were also sesquiterpenes (88.9 and 90.4%, respectively) including germacrene D, bicyclogermacrene, -caryophyllene, and -farnesene [15]. P. tuberosa. EO was waxy, light-yellow, weak aroma; yield 0.02% of air-dried raw material mass. EO contained 26 compounds, of which 22 were identified (92.2% of the total number). The predominant compounds were phytol (35.5%), linalool (7.7%), eugenol (7.2%), caryophyllene oxide (7.1%), oct-1-en-3-ol (5.2%), dihydroactinidiolide (4.2%), and -terpineol and geraniol (4.1% each) (Table 1). The EO composition of P. tuberosa was similar to that of Chinese species of the genus