Abstract: Tea tree oil(TTO)is a colorless to pale yellow essential oil extracted from the fresh leaves of the genus Melaleuca. TTO has a broad-spectrum antibacterial activity,and it has a good killing or inhibiting effect on many bacteria and fungi. It has a large use in biomedical science,pharmaceutical,cosmetic,food,agricultural and veterinary applications as preservatives,antibacterials and fragrances.This paper reviews the antibacterial activity and mechanism,antiviral activity and antiparasitic activity of tea tree oil on bacteria and fungi in recent years,and summarizes the main active substances of the anti-microbial action of tea tree oil. This paper is aiming at providing reference for the application of tea tree oil in reducing resistance.