In this study, we evaluated the nutritional components and functional activities of Wooung (burdock, Arctium lappa L.) and Jerusalem artichoke (Helianthus tuberosus L.) tea. Roasting burdock’ contained 75.87% carbohydrates; in addition, the moisture content, crude fat, crude protein, and crude fiber were 10.43%, 1.77%, 8.50%, and 3.43%, respectively. Roasting Jerusalem artichoke showed 77.477% carbohydrate content, with moisture content, crude fat, crude protein, and crude fiber of 10.67%, 1.23%, 7.83%, and 2.80%, respectively. Roasting burdock’s water-soluble dietary fiber content was 4.8 g/100 g and insoluble dietary fiber content was 1.5 g/100 g; whereas, roasting Jerusalem artichoke’ water soluble dietary fiber content was 2.4 g/100 g and insoluble dietary fiber content was 1.6 g/100 g. The highest mineral contents in roasting burdock and Jerusalem artichoke were potassium and magnesium, in order. The results of amino acid analyses s indicated a total of 25 types in roasting burdock, with total amino acid content of 1,382.112 mg/100 g, and essential amino acid content of 766.031 mg/100 g. In total, 24 types of amino acids were separated and identified in roasting Jerusalem artichoke, with total amino acid content of 2,678.018 mg/100 g, and total essential amino acid content of 157.294 mg/100 g. Roasting burdock and Jerusalem artichoke’ polyphenol contents were 32.56 and 29.56 mg GAE/g each, and their flavonoid contents were 16.54 and 16.71 CE/g each. IC50 values of DPPH radical-scavenging activity of roasting burdock and Jerusalem artichoke were 12.99 and 19.74, respectively; and IC50 values of hydroxyl radical-scavenging activity were 25.96 and 22.93, respectively.