Abstract: In order to clarify the nutritional composition of purple skin onions from different geographical origins and identify characteristic components that contribute significantly to the identification of production areas, purple skin onions from four geographical origins of Hebei, Shandong, Yunnan, and Gansu were studied for their texture, color, water content, chemical characteristic indicators（total phenol content, total flavonoid content, and reducing sugar content）,and chemical element composition. The results showed that, there were no significant differences in water content, pH value and texture characteristics of purple skin onions from different geographical origins, but significant differences in soluble solids, total phenols, total flavonoids, reducing sugar contents and chemical element composition. Among them,purple skin onions from Hebei have a brighter color, the highest content of soluble solids and the richest content of chemical element. The contents of total phenols and flavonoids in Yunnan purple skin onions were the highest. The content of reducing sugar in Shandong purple skin onions were the highest. 25 chemical elements were identified as markers of purple skin onions from different geographical origins in Hebei, Shandong, Yunnan, and Gansu. Hebei purple skin onions have better appearance, high edible quality and rich nutritional value, while Yunnan purple skin onions have higher medicinal value.