Background & Aim: Staphylococcus aureus is one of the bacterial pathogens and the most important factor in hospitalized infections in human community. This bacterium is becoming resistance to chemical drugs quickly. Lots of countries are trying to find new compositions as a suitable replacement for these antibiotics. The aim of this study was antibacterial activity and chemical composition of (Thymus vulgaris L.) and (Thymus daenensis Celak) cultivated in Iran. Experimental: The aerial parts of T. vulgaris and T. daenensis were collected from stages beginning of blooming set at Estahban (Fars province) in South Iran, during 2014.The essential oil was extracted by a Clevenger approach and analyzed using GC/MS. This essential oil was examined on S. aureus with different sensitivity levels to vancomycin, methicilin and oxacillin antibiotics. Results & Discussion: In T. vulgaris and T. daenensisoil, 28, 26 compounds were identified, respectively. The major constituents of the T. vulgaris oil were thymol (63.14%), p-cymene (9.45%), g-terpinene (8.67%) and carvacrol (3.14%).The major constituents of the T. daenensis oil were; thymol (71.2%), g-terpinene (8.81%), p-cymene (3.8%) and carvacrol (2.4%). According to these results, MIC and MBC of T. vulgaris and T. Daenensis oil on S. aureus were estimated 0.1 to 0.5 micro l/ml respectively. Industrial and practical recommendations: In conclusion, the results obtained in our study indicated that Thymus daenensis oil had a high suppressing and fatal effects. پرونده مقاله