This study was to elucidate the anti-inflammatory activities of a methanol extract derived from the fermented bark of Dioscoreae batatas on LPS-induced activation in macrophages. It was fermented with Lactobacillus fermentum and L. plantarum and then analyzed to identify the contents of methanol extract and diosgenin. The fermented product showed 3-fold increase in the extraction yield by methanol, and 1.8-fold increase in diosgenin contents, compared to that from the dried bark of D. batatas. Although the methanol extract from the unfermented D. batatas inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and TNF-${alpha}$ in J774 A.1 cells, the methanol extract from the fermented product revealed significantly the enhanced the inhibitory activities on LPS-induced production of NO and TNF-${alpha}$. Taken together, our results indicate that fermentation of bark of D. batatas elevates the functional activity inhibiting macrophage activation through the increase of the content of anti-inflammatory compounds. Thus, its methanol extract may be useful as a functional material for the therapy of inflammatory diseases.