Analysis of the various constituents and determination of biological activities in the different parts (root, stem, and leaf) of Allium victorialis var. platyphyllum were carried out. Potassium and calcium were detected in higher contents (mg/100 g fresh wt.) than other minerals. The total phenolic content (mg tannic acid eq./100 g dry wt.) decreased in the order of leaves (792.7±16.6) > stems (160.3±6.8) > roots (101.5±2.7), and the total flavonoid content (mg quercetin eq./100 g dry wt.) was as follows: leaves (497.9±11.1), roots (35.7±0.4), stems (18.5±1.4). DPPH radical-scavenging activity and inhibition activity against the formation of cholesteryl ester hydroperoxide in rat blood plasma was higher in the leaves than in roots and stems. Extracts of A. victorialis separated by parts displayed antimicrobial activity against Clostridium perfringens, Staphylococcus aureus, Listeria monocytogenes, Vibrio vulnificus, Vibrio parahaemolyticus, of which the strongest activity was against C. perfringens.