The present invention relates to plant extracts for treating diabetes and processes for making same. In particular, the plant extract is prepared from roots of Mirabilis jalapa L., which has the efficacies of lowering blood glucose, improving insulin sensitivity, and increasing glycogen content in skeletal muscle.本發明係關於一種用於治療糖尿病之植物萃取物及其製備方法。該植物萃取物係來自煮飯花(Mirabilis jalapa L.)之根部,具降低血糖、增加胰島素敏感度、以及增加骨骼肌肝醣含量之功效。