Use of the essential oils of Salvia genus in medical, culinary, food and cosmopolitic products and their biological activities depends on the chemical constitutes, therefore based on the importance of these essential oils, for determination the quantity and quality of the essential oil of Salvia lachnocalyx Hedge, we collected the aerial parts of plant in May from Fars province. Then the essential oil was isolated by water distillation and analyzed by GC and GC/MS. The thirty-four compounds were identified in the essential oil concluded 99.7% of the total oil. The major components were bicyclogermacrene (31.3%), a-pinene (13.2%), sabinene (11.7%) and b-pinene (10.3%). Other constitutes were a-terpinyl acetate (7.0%), b-caryophyllene (7.4%), limonene (2.8%) and 1,8-cineole (2.3%).