The root of Aster tataricus L. f. (recorded in all versions of Chinese Pharmacopoeia) is a traditional Chinese medicine with the function of dispelling phlegm and relieving cough for more than 2000 years. Shionone is one of the principal components. It was extracted from Aster tataricus and possesses anti-inflammatory effects. The anti-inflammatory mechanism of shionone was related to a decrease in the phosphorylation level of ERK1/2 protein and IκBα and the protein expression of iNOS. In addition, shionone can inhibit the activity of ubiquitin-specific protease 2 (USP2) and provide a lead compound for the future development of new USP2 inhibitors.