Abstract: Artemisia, a plant widely used as traditional herbal medicine in many countries, has drawn attention of the researchers. And its extracts or compounds are known to have an efficacy of antioxidant, anti-diabete, anti-cancer, anti-inflammation and neuroprotection. Sumaeyaksuk is a variant of the Artemisia argyi and major constituents are eupatilin and jaceosidin. This study was performed to investigate the effects of the sumaeyaksuk aqueous extract on inflammatory response induced by lipopolysaccharide (LPS) in human hepatoma HepG2 cells. To examine the potential hepatoprotective properties of sumaeyaksuk extract, cell viability, as well as nitric oxide (NO), reactive oxygen species (ROS), macrophage colony-stimulating factor (M-CSF), interleukin-8 (IL-8) levels, alanine transaminase (ALT), and aspartate transaminase (AST) activities, were measured. Cytotoxic activity of extracts on HepG2 cells was measured by MTT assay. Sumaeyaksuk extract did not induce cytotoxicity at concentrations of 0~400 μg/mL. NO and ROS levels significantly decreased with increasing concentration of the extract. The secretion levels of M-CSF and IL-8 were suppressed by sumaeyaksuk extract in a dose-dependent manner. Moreover, ALT (75.4%) and AST (61.6%) levels significantly decreased in sumaeyaksuk extract-treated cells at 400 μg/mL. These results suggested that the sumaeyaksuk extract attenuates the LPS-induced hepatotoxicity resulting from regulation of inflammatory factors and could potentially be used as a hepatitis therapeutic agent.