The anti-inflammatory effects of Undaria pinnatifida water extract (UPWE) were investigated using lipopolysaccharide -induced inflammatory response in this study. To examine the potential anti-inflammatory properties of UPWE, the cell proliferation, nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and IL-1β were measured. As a result, there was no cytotoxicity in the macrophage proliferation treated with UPWE compared to the control. NO levels decreased with increasing concentration of UPWE. Moreover, the secretion of IL- 6, TNF-α and IL-1β were suppressed in a dose-dependent manner, and IL-6 inhibition activities were over 50% at 0.1%. These results suggested that UPWE may have significant effects on inflammatory factors and be a potential anti-inflammatory therapeutic materials.