Abstract: Supercritical carbon dioxide extraction (SCDE) technique was used to eatract the essential oil from oregano, clove, Forsythia suspense, Litsea cubea and cinnamon. The diameter of inhibition cycles of the five spices essential oils on various bacteria was investigated. The influences to the level bacteriostaic were studied by heating and changing the pH value. The anti-oxidation effects of the five spices essential oils were studied too. The results showed that the five spices essential oils have strong bacteriostatic action on the tested bacteria, mold and microzyme. The order of level bacteriostatic was studied as follows: cinnamon>clove>oregano, Forsythia suspense and Litsea cubea. All the five spices essential oils have the strongest level bacteriostatic on mold and definite anti-oxidation ability. The level bacteriostatic of the five spices essential oils are getting stronger with the lowering of pH value and not changed obviously by heating at 121℃ for 15 minutes.

Key words: spices essential oil, bacteriostasis, anti-oxidation, natural preservative