Objectives: The purpose of this study was to investigate the effects of Longanae Arillus water extract (LA) on the production of inflammatory mediators in RAW 264.7 cell. LA is used for forgetfulness, insomnia, palpitation symptoms in korean medicine. Methods: In order to evaluate cytotoxicity of LA, cell viability was measured. To investigate anti-inflammatory effects of LA in the lipopolysacharide (LPS)-induced RAW 264.7 cell, the concentration of nitric oxide (NO) and cytokines were measured. And when p-value is below 0.05, it is judged to have the significant difference statistically. Results: 1. LA showed no cytotoxicity. 2. LA inhibited significantly the production on NO at the concentration of 50 and $200{mu}g/ml$. 3. LA inhibited significantly the production on interleukin (IL)-$1{eta}$ at the concentration of 25, 50, 100 and $200{mu}g/ml$. 4. LA inhibited significantly the production on tumor necrosis factor (TNF)-${alpha}$ at the concentration of 50, 100 and $200{mu}g/ml$. 5. LA inhibited significantly the production on lipopolysaccharide-induced chemokine (LIX) at the concentration of 25, 100 and $200{mu}g/ml$. 6. LA inhibited significantly the production on regulated on activation normal T cell expressed and secreted (RANTES) at the concentration of $200{mu}g/ml$. Conclusions: These results suggest that LA has anti-inflammatory effect.