Jangjingki (Oxalis corniculata L.) is a plant from Oxalidaceae that has potential as a natural antimicrobial agent. The purpose of this research is to see the antimicrobial activity of methanol extract of jangjingki against the growth of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231. The thick extract of jangjingki was obtained by the maceration method with methanol solvent. At the same time, the antimicrobial activity test on S. aureus and E. Coli bacteria was carried out using the hole diffusion method. The simplicia characterization showed 7.17% water, 9.68% of total ash, 11.67% water-soluble extract, and 9.17% of the ethanol-soluble section. At the same time, the methanol extract of jangjingki characterization showed 22.5% of water, 10.16% of total ash, 55.83% water-soluble extract, and 62.91% of the ethanol-soluble section. Phytochemical test results showed that the methanol extract of jangjingki contains alkaloids, saponins, flavonoids, tannins, and steroids. The results of the antimicrobial activity test with variations in the concentration of jangjingki methanol extract 15, 20, 30, and 40% on S. aureus and E. Coli bacteria showed growth inhibition activity of these two bacteria, the largest diameter of the inhibition zone was formed when the extract was given a concentration of 40% with a diameter of the area. Resistance of 8,07 mm and 11 mm, respectively. Meanwhile, the test results of inhibition of growth of the fungus C. Albicans by presenting variations in the concentration of jangjingki methanol extract of 5, 10, 15, and 20% could not inhibit the growth fungus C. Albicans.