Tumor necrosis factor-alpha (TNF-${alpha}$) is a major mediator of immuno-inflammatory activity. The purpose of this study is to investigate whether TNF-${alpha}$ productions of mouse macrophage RAW 264.7 and human hepatocyte HepG2 are modulated by Artemisiae argi Folium water extract (AW), Lactobacillus pentosus-fermented Artemisiae argi Folium water extract (AFL), and Saccharomyces cerevisiae-fermented Artemisiae argi Folium water extract (AFS) for 3 h of incubation. Effect of AW on cell viability of HepG2 was also investigated. TNF-${alpha}$ productions were measured by Enzyme-Linked Immnunosorbent Assay method and cell viability was measured by MTT assay. Both AFL and AFS significantly increased TNF-${alpha}$ productions of RAW 264.7 at the concentration of 50, 100, and 200 ${mu}g$/mL (p<0.05). Also, AFL and AFS significantly increased TNF-${alpha}$ productions of HepG2 at the concentration of 50, 100, and 200 ${mu}g$/mL (p<0.05). AW significantly increased TNF-${alpha}$ production of HepG2 at the concentration of 100 and 200 ${mu}g$/mL (p<0.05). AW did not show any cytotoxicity on HepG2 cells for 3 h. These results suggest that AFL, AFS, and AW have the immune-enhancing property related with its increasing effect on TNF-${alpha}$ production of macrophage and hepatocyte.