The study is aimed to evaluate the safety and efficiency of autologous bone marrow mononuclear cell transplantation in treating selective patients with type 2 Diabetes Mellitus. We hypothesized that autologous bone marrow stem cell transplantation would promote β-cells regeneration by directly differentiated from the transplanted BMMCs or stimulate local stem cells regeneration and thus decrease or eliminate the need of exogenous insulin and improve β-cells function.

To study the safety and efficacy of bone marrow mononuclear cell transplantation in type 2 diabetics. According to the intervention and baseline characteristics, patients are divided into 4 arms.

Inclusion Criteria:

• Type 2 diabetes mellitus
• age 30-70
• stable doses of medication for at least 3 months
• BMI <35 and >18.5

Exclusion Criteria:

• secondary cause for hyperglycemia
• pregnancy or nursing
• positive autoimmune antibody of diabetes
• severe complication or concurrent diseases
• active infection or febrile illness
• allergy to iodine
• history or signs of aortic aneurysm
• history or active pancreatic diseases
• known substance abuse or alcoholism or heavy smoking
• not suitable for other conditions upon investigators' expertise