Most of the aromatic species of Lamiaceae families have the best medicinal performance. The reason of the inclination of World Health Organization (WHO) to medicinal plants is the diseases caused by unduly consumption of chemical medicines the world. To do this, the first stage is the exact identification of extracting effective medicinal substances and qualitative and quantitative diversity of them in special habitats. Therefore, the chemical composition of the volatile oil from flower parts of Perovskia atriplicifolia Benth. and Perovskia abrotonoides Karel. have been studied by GC and GC-MS. Forty-one composition of P. abrotonoides Karel. were identified. 1,8-Cineole (14.41%), δ-3-Carene (8.63%), β-Caryophyllene (8.18%) and α-Humulene (8.33%) were found to be the major constituents of the oil. Twenty-four components of P. atriplicifolia Benth. were identified and the major constituents of the oil 1,8-Cineole (18.65%), δ-3-Carene (11.23%), α-Pinene (9.98%) and Viridiflora (8.45%) were found. The oil of P. abrotanoides determined by a high content of monoterpens (61.85%) and it is a medicinal herb to treat leishmaniasisin. On the other hand, sesquiterpenes comprise only (38.15%) of the essential oil. The oil of P. atriplicifolia was characterized by a high content of monoterpenes (67.26%), whereas sesquiterpenes contained only 32.74% of the essential oil. Also, this species is used as a cooling medicine in the treatment of fevers and as an analgesic in rheumatic pains. The ethnopharmcological and chemotaxanomic importance of the genus Perovskia prompted us to re-investigate the chemical constituents of P. abrotanoides and P. atriplicifolia.