Euphorbia hirta L., a species belonging to genus Euphorbia, Euphorbiaceae family, has been found a lot in the Mekong Delta. From the ethyl acetate and methanol extracts of this plant, four pure compounds were isolated and identified their chemical structures by spectroscopic techniques including quercitrin (1), luteolin (2), quercetin (3) and caffeic acid (4). The effect of crude ethanolextract and some fractioned extracts as well as four isolated compounds from E. hirta L., collected in the Mekong Delta, on endoplasmic reticulum stress-induced cell death in mouse β-cell lines was investigated. The results showed that methanol extract and an isolated compound, quercitrin gave strong cell-protective effect with the cell viability of 69 % and 78 % at the dose of 100 µg/mL and 10 µg/mL, respectively. This proves that E. hirta L. might have antidiabetic effect and worth conducting further pharmacological investigations related to type 2 diabetes mellitus.