Glucose-6-phosphatase (G6Pase), an enzyme found mostly in the kidneys and the liver, acting significant role of supplying glucose through starvation. This study includes (84) subjects, their age ranged from (40 to 54) years. (20) subjects were healthy chosen as control group and (64) patients with type 2 diabetes mellitus were divided into three groups according to their type of anti diabetic therapy : (23) newly diagnosed group without therapy (Group1), (20) with metformin therapy (Group2) and (21) with metformin plus glibenclamide therapies( Group3). The study found that G-6-Pase activity is increased, thereby leading to an increase in endogenous glucose production (EGP) in patients with type 2 diabetes and, therefore FPG will increase. The result found that increasing G-6-Pase activity will increase the concentration of glucose in the blood and that will increase the long-term glycemic control (HbA1c%).