In this study, we have verified the memory and cognitive enhancing effect of Longanae Arillus, the fruit of Euphoria longana Lamarck, which has been used as a tonic and for the treatment of amnesia, insomnia, and palpitations in oriental medicine. To investigate the effect of Longanae Arillus water extract(LAE) on the memory and cognitive dysfunction, scopolamine (1 mg/kg, i.p.) was injected in C57BL/6 mice and several behavior tests including Y-maze, Morris water-maze, passive avoidance and fear conditioning tests were conducted. Administration of LAE (100 or 200 mg/kg/day, p.o.) effectively improved scopolamine-induced memory impairment and dysfunction. To further determine the possible molecule mechanism of LAE, we have examined the activity and/or mRNA expression of diverse proteins involved in the acetylcholine metabolism. LAE particularly increased the amount of acetylcholine in the cortex which was mediated by suppression of acetylcholine esterase (AchE) activity. In addition, LAE elevated the mRNA expression of muscarinic acetylcholine receptors (mAchRs) without affecting the mRNA levels of choline acetyltransferase (ChAT) and acetylcholine esterase (AchE). In another experiment, LAE effectively inhibited mRNA expression of pro-inflammatory cytokines such as tumor necrosis factor-${alpha}$ (TNF-${alpha}$) and interleukin-$1{eta}$ (IL1-${eta}$), which seemed to be mediated by inhibition of upstream transcription factor NF-${kappa}B$ and extracellular-regulated kinase 1/2 (ERK1/2). These results demonstrate that Longanae Arillus can increase acetylcholine amount the cortex via regulation of AchE activity as well as mAchRs expression and decrease pro-inflammatory responses via inhibition of NF-${kappa}B$ signaling pathway, thereby having therapeutic potential to improve memory and cognitive deficit in amnesia.