Background and Objectives: Essential oils (EOs) with different biological activities, such as antibacterial properties, are a valuable resource for developing new drugs. Materials and Methods: Ingredients of six medicinally important EOs, including Artemisia dracunculus, Anethum graveolens, Citrus limon, Citrus sinensis, Cinnamomum zeylanicum and Zingiber officinale , were identified using GC-MS analysis. Moreover, their five major compounds were also listed. Furthermore, the half-maximal inhibitory concentration (IC50) against four important human bacteria was also investigated using the 96-well plate microdilution. Results: C. sinensis EO with IC50 of 1.0 and 4.7 mg.mL–1 have the most effect on the growth of S. aureus and P. aeruginosa. Moreover, EOs of Cinnamomum zeylanicum (IC50: 1.0 mg. Ml–1) and Artemisia dracunculus (IC50: 1.3 mg.mL–1) significantly showed better inhibitory effect on E. coli and K. pneumoniae. Conclusion: These EOs could be used for developing inexpensive, potent, and green antibacterial agents.