Abstract: The dietary fiber has many medical functions in treating illnesses like diabetes, intestines problems, obesity, cardiovascular diseases, gall-stone, cancer and constipation. However, when it comes to the treatment of diabetes, different dietary fiber of different sources and origins vary drastically in their alleviating effects. Soluble dietary fibers are of better effects in hypoglycemic activity than insoluble ones. The development of the dietary fiber resources, new preparatory methods, the expansion of its distinctive uses and physiological functions, research of commercial production and the economic value of exploration have now become research hotspots.