Background : Arctii Radix (the dried roots of Arctium lappa L., AR) is used in traditional medicine to treat oxidative stress related diseases including cancer. Therefore, this study focuses on the antioxidant potential of AR as extraction solvents. Methods and Results : To increase the extraction amount of active ingredient, the AR were extracted by ethanol (ARE) and water (ARW). In order to determine active ingredient content of AR, we were carried out total polyphenolic (TPC) and flavonoid content (TFC) analyses. As a result, TPC (47.74 ± 1.02 g․GAE/㎏ extract) and TFC (19.34 ± 0.30 g․CTE/㎏ extract) of ARE were found significantly higer as compared to ARW. The IC50 values based on the DPPH (59.00 ± 3.25 ㎍/㎖), ABTS (93.20 ± 1.30 ㎍/㎖), ROS (57.78 ± 3.44 ㎍/㎖) and ONOO- (14.56 ± 1.24 ㎍/㎖) for ARE were generally stronger showing potential antioxidant properties compared to ARW. Conclusion : Data from results revealed Arctii Radix ethanol extracts act as an antioxidant agent due to its free radical scavenging activity.