Abstract: [Objective] To explore the antibacterial function of lavender essential oil and its antibacterial effect on plant pathogenic fungi in order to provide the basis for the development of natural antibacterial agents.[Method]The antibacterial activity of lavender essential oil was studied by the method of mycelial growth rate, which was applied to 6 plant pathogenic fungi.[Result]Under the volume fraction of 5 μL/mL, the lavender essential oil was treated with a total of 5 d, which had an inhibitory effect on cotton Rhizoctonia solani, Alternaria alternata and Alternaria solani(EllisetMartin)Jonesetgrout.The results showed that the content of the essential oil was 100;.The minimum inhibitory concentration (MIC) determinations showed that the inhibitory effects of lavender essential oil on 6 kinds of tested bacteria from strong to weak were cotton Rhizoctonia solani, Alternaria alternata, Alternaria solani(EllisetMartin)Jonesetgrout, Pyricularia oryzac Cavgra, Verticillium dahliae Kleb and Fusarium oxysporum.[Conclusion]Lavender essential oil has a good inhibitory effect on plant pathogenic fungi, so, good application potential will be found in pesticide application.