Obesity is one of the characteristics of type 2 diabetes mellitus. Most of the obese diabetes patients are combined with dyslipidemia or hypertension. The clustering of diabetes, obesity, hypertension and dyslipidemia increases the risk of cardiovascular events for patients. GLP-1 (glucagon like peptide-1) is a kind of incretin discovered in recent years. It was reported that beside its hypoglycemic and losing weight effects, activator of GLP-1 receptor could decrease blood pressure and improve lipid metabolism. Therefore, activation of GLP-1 receptor may become a new comprehensive treatment strategies for improving glucose and lipid metabolism, blood pressure level and cardiovascular complication. But, it is lack of evidence-based medicine proof on the relationship between GLP-1 and blood pressure or serum lipid. So, investigators designed a prospective, randomized, open-label, active control study, and try to evaluate the effects of activator of GLP-1 receptor (liraglutide) on lowering blood pressure, improving vascular function and lipid metabolism in overweight or obese type 2 diabetic patients with masked hypertension.

Inclusion Criteria:

1. Male or female, age between 35-60 years old
2. Type 2 diabetes
3. 24kg/m²≤BMI≤32kg/m², or WC≥90cm for male and WC≥85cm for female
4. Grade 1 hypertension or masked hypertension diagnosed via 24-h ambulatory blood pressure monitoring (daytime blood pressure load 50%≥135/85 mmHg, night time blood pressure load 50%≥125/75 mmHg or 24h blood pressure load 50%≥130/80 mmHg）

Exclusion Criteria:

1. Type 2 diabetes with serious complications, such as diabetic neuropathy, diabetic retinopathy, stage IV diabetic nephropathy, or acute diabetic complications.
2. Type 1 diabetes.
3. Diagnosed moderate to severe sleep apnea syndrome(SAS).
4. Grade 2 or Grade 3 hypertension.
5. Triglyceride≥5.65mmol/L
6. History of cardio-cerebral vascular events such as congestive heart failure, myocardial infarction or stroke within 3 months.
7. Hypohepatia (AST or AST is twice higher than the upper limit) or history of hepatitis or cirrhosis, hepatic encephalopathy.
8. Renal insufficiency ( serum creatinine is 1.5 times higher than the upper limit) or history of dialysis and nephritic syndrome.
9. Chronic obstructive pulmonary disease (COPD), chronic respiratory failure or hyoxemia.
10. Acute infections, tumor, severe arrhythmia, mental disorders, alcohol or medicine addiction.
11. Fertile woman without contraceptives.
12. Any surgical or medical conditions that significantly influence absorption, distribution, metabolism or excretion of the intervention drugs.
13. Allergic to or have contraindication to the intervention drugs.