Diabetes mellitus (DM) is a chronic disease characterized by blood glucose levels that exceed normal. One alternative treatment is to use herbs that have the potential as hypoglycemic compounds. Sungkai is one of the plants used by the Dayak tribe for generations to treat diabetes. This study aims to determine whether each organ of the Sungkai plant has the potential as a diabetes drug. The parameters measured in this study were antioxidant activity and total phenolics. This study used a completely randomized design with 25 white rats (Rattus norvegicus) as diabetic animal models, which were divided into five treatment groups which included normal rat (K-), DM positive rat K(+), and DM rat + soaking water from Sungkai leaf, DM rat + soaking water from Sungkai stem, and DM rat + soaking water from Sungkai root. The data obtained were analyzed statistically by ANOVA with sequence, normality test, homogeneity, and further test using Duncan's test. The results showed that the antioxidant activity and total phenol of each part of the Sungkai plant were significantly different (p<0.05). The highest antioxidant activity is found in the leaves. Blood glucose levels of DM rats decreased after 30 days of Sungkai treatment. Sungkai plant has different antioxidant activity in each organ, and the Sungkai plant has hypoglycemic potential in overcoming diabetes mellitus.