This study describes a preliminary evaluation of the anti-inflammatory activity of Acrosorium yendoi Yamada extracts. A. yendoi Yamada was extracted using 80% ethanol and then fractionated sequentially with n-hexane, ethyl acetate and butanol. To screen for anti-inflammatory agents effectively, we first examined the inhibitory effect of 80% EtOH extract and solvent fractions of A. yendoi Yamada on the production of pro-inflammatory factors and cytokines stimulated with lipopolysaccharide. In addition, we examined the inhibitory effect of 80% EtOH extract and solvent fractions of A. yendoi Yamada on pro-inflammatory mediators (NO, iNOS, PGE2, and COX-2) in RAW 264.7 cells. In the sequential fractions of n-hexane and EtOAc inhibited the NO and PGE2 production and the protein level of iNOS and COX-2, and protein expression of pro-inflammatory cytokines (TNF-α, and IL-6). These results suggest that A. yendoi Yamada may have significant effects on inflammatory factors and may be provided as possible anti-inflammatory therapeutic seaweed.