Euphorbia hirta L., a species belonging to the genus Euphorbia, family Euphorbiaceae, has been found a lot in the Mekong Delta of Viet nam. The aim of this study was to investigate the chemical constituents of E. hirta collected in Can Tho city. By column chromatography, five compounds were isolated, including taraxerol (1), campesterol (2), cycloart-23-ene-3β,25-diol (3), afzelin (4) and myricitrin (5). Their chemical structures were elucidated by spectroscopic data analysis and by comparison with those reported in the literature. Among five compounds, compound (3) was isolated for the first time from this species. In addition, compound (1) was conducted for antimicrobial activity.