Abstract: Euphorbia hirta L. is a plant used in traditional medicine and proven pre-clinically for antiinflammation, asthma, wound healing and diarrhea. It also has antioxidant activity. However, the anti-diabetes mechanism of this plant has not been elucidated. A reliable technique to elucidate the anti-diabetes mechanism in the traditional medicine is required. Therefore, a new technique which was based on the glucose tolerance test was explored. Through various oral glucose tolerance test loading, the anti-diabetes properties of Euphorbia hirta L. could be elucidated. From the in vitro experiment, it was known that the ethanol extract and ethyl acetate fractions are the fractions with α-glucosidase inhibition activity, while n-hexane, chloroform, butanol and water fractions does not have α-glucosidase inhibitory effect. Therefore, only ethanol extract and ethyl acetate fractions were used for the in vivo tests. Based on the in vitro and in vivo test, Euphorbia hirta L. ethanolic extract and ethyl acetate anti-diabetes mechanism is related to its antioxidant capacity and also its α-glucosidase inhibitory properties.