In this study, we investigated the anti-inflammatory effects of fermented Hizikia fusiformis extracts in lipopolysaccharide (LPS)-stimulated RAW 264.7 mouse macrophages. The fermentation was performed using Lactobacillus casei in mixture of carbon source at 30 o C for 30 days. The sample groups were prepared with/without L. casei group in order to demonstrate the anti-inflammatory activity of fermented H. fusiformis in regard to lactic acid bacteria. As a result, we confirmed the inhibitory effect of H. fusiformis extracts on LPS-stimulated NO production and expression of TNFα, while it had no regulatory effect on the expression of iNOS, COX-2, IL-1β and IL-6 as important inflammatory factors. However, L. casei fermented group significantly suppressed the expression of the above factors. In particular, the difference between the two groups in the matter of mRNA expression of iNOS, which is directly associated with NO production, indicated that the fermentation with lactic acid bacteria effectively suppressed NO production by regulating iNOS expression. Also, effective suppression of pro-inflammatory cytokines showed that the fermentation using L. casei may provide an increment towards extraction of active ingredients that are effective anti-inflammatory agents.