Objectives : The purpose of this study is to investigate the effect of Fermented Houttuyniae Herba Water Extract (HL) on production of proinflammatory mediators in mouse macrophage RAW 264.7 cells. Methods : Cell viabilities were measured by MTT assay. Effect of HL on nitric oxide (NO) production from RAW 264.7 cells was accessed by Griess reagent assay. Effect of HL on productions of inflammatory cytokines such as interleukine (IL)-17, Interferon $gamma$-inducible protein (IP)-10, Eotaxin, IL-5, Monocyte Chemotactic Protein-3 (MCP-3), and IL-13 in LPS-induced RAW 264.7 cells was accessed by a multiplex bead array assay based on xMAP technology. Results : The results of the experiment are as follows. 1. Incubation with HL for 24 hours showed significant increase in cell viability of RAW 264.7 mouse macrophages (P < 0.05). 2. HL showed to inhibit NO production from RAW 264.7 cells at the concentrations of 25 and 50 ug/mL significantly (P < 0.05). 3. HL inhibited significantly NO production in LPS-induced RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ug/mL (P < 0.05). 4. HL inhibited significantly IL-17, IP-10 and Eotaxin in LPS-induced RAW 264.7 cells at the concentrations of 25, 50, 100 and 200 ug/mL (P < 0.05). Conclusions : These results suggest that HL has anti-inflammatory moiety related with its inhibition of NO, IL-17, IP-10, and Eotaxin in macrophages.