Diabetes,the source of many deadly diseases,has been considered as the most dangerous epidemics in the world.The therapeutic approaches are varied according to different type of diabetes.But insulin therapy is always an important treatment method for both types of diabetes.Oral administration is an ideal route but limited by the intrinsic instability of insulin.Therefore,subcutaneous (sc) injection is still the main route for insulin administration.Nowadays,however,the diabetic patients have to receive injections for as lease once a day,which brings lots of troubles and pains and leads to a very low patient compliance.