Maesa japonica (Thunb.) is an evergreen shrub belonged to the Myrsinaceae family, which was discovered in2006 in South Korea. And, its biological functions have not been well studied. In this study, we determined the antioxidantactivities, α-glucosidase inhibitory effects and antimicrobial activities of methanol extract and the solvent fractions of M.japonica leaves and twigs. The highest antioxidant activity obtained by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scav-enging assay and reducing power assay was found in the ethylacetate fraction of twigs methanol extract, which contained thehighest level of total phenolic compounds compared to the other fractions. In addition, ethylacetate fraction of twigs extractexhibited higher inhibitory activities against α-glucosidase (IC50=0.8㎍/㎖) compared to the IC50 of the buthanol fraction(IC50=16㎍/㎖) of leaves extract. It showed antimicrobial activities against Bacillus atrophaeus and Bacillus subtilis subsp.Spizizenii. Although the data is too limited, the current study is the first report on biological functions of M. japonica.