The present invention relates to an antidiabetic composition containing extracts of 15 kinds of medicinal and/or edible natural products as an active ingredient, and more specifically, an extract obtained by treating 15 kinds of medicinal and/or edible natural products at high temperature and high pressure. It relates to a pharmaceutical composition and health functional food for preventing or treating/improving diabetes containing as an active ingredient. The pharmaceutical composition for preventing or treating diabetes of the present invention and 15 kinds of medicinal and/or edible natural product extracts as active ingredients of health functional foods, as demonstrated through the examples of the present specification, prevent type 2 diabetes or It has excellent effects that can be used as therapeutic/improving medicines and health functional foods. In addition, 15 kinds of medicinal and/or edible natural product extracts of the present invention have no human red blood cell hemolytic activity, excellent thermal stability, and no loss of starch-degrading enzyme inhibitory activity even in acidic conditions of pH 2 and plasma, liquid, Since it can be easily processed into various forms such as cream, powder, pills, and tablets, it can be very useful in the pharmaceutical industry and food industry.