Essential oils, a series of aromatic oily liquids extracted from aromatic plants, are fine natural antimicrobial materials. Essential oils have many advantages in the antimicrobial aspect: (1) have strong and broad range of antimicrobial activity; (2) have a fumigating characteristic and aromatic odor; (3) be natural and environmental friendly; (4) easy to be extracted from wide sources. Based on these advantages, essential oils have great potential applications in the antimicrobial field. In this paper, we overviewed the latest progress of researching about essential oils from several aspects, such as the distribution and chemical composition, the antibacterial and antifungal activity, as well as relationship between the chemical compositions and antimicrobial activity. This review could promote the application of essential oils in broad antimicrobial field and provide a reference for the scientists engaged in the research of essential oils.