Abstract: Diabetes Mellitus (DM) is a group of metabolic disorder characterized by hyperglycemia due to damage in insulin secretion, insulin action or both. One of the diabetes mellitus group is diabetes mellitus type 2. Diabetes accounts type 2 for most of the data of DM patients which reached 90-95% of the total diabetics population. One of the plants as a potential alternative antidiabetic drugs is (Cynometra cauliflora) Namnam plant. This research will test the ability of glucose absorption by muscles of the isolated diaphragm of Sprague Dawley rat by Namnam (Cynometra cauliflora) leaf methanol extract at various concentrations. The result shows that an increase in glucose uptake by diaphragm when concentration of Namnam (Cynometra cauliflora) leaf extract and the highest increases in the concentration of 450 mg dL–1 with the uptake of 42.54±3.23 mg dL–1/30 min. Increased uptake of glucose also occurs when insulin 0.25 IU mL–1 is combined with methanol extract of namnam leaf (EMDN) at concentration of 450 mg dL–1 of 92.19±9.74 mg dL–1/30 min. Therefore, the namnam leaf (Cynometra cauliflora) plant has potential as antidiabetes type 2 drug through mechanism of the increased glucose uptake into cells.