Essential oil (EO) of Ageratum conyzoides L. leaves was analyzed by gas chromatography – mass spectrometry (GC-MS) method. Physicochemical properties (acid value, saponification value, ester value, density and freezing point), antioxidant capacity and antibacterial capacity were determined. In general, 34 compounds were identified in EO of this material. Moreover, EO has the antioxidant capacity, and the antimicrobial activity was determined by the paper disc diffusion method for antibiotic susceptibility testing. Essential oil does not affect the growth of Staphylococcus aureus - ATCC 25923, Bacillus subtilis - ATCC 11774 and Escherichia coli - ATCC 25922. However, the result also shows that EO of A. conyzoides leaves can inhibit the growth of Salmonella enteritidis - ATCC 13076.