The application relates to a use of black soybean hull extracts in the manufacture of foods, health care products and medicaments. The black soybean hull extracts can be added to foods or drinks, and also can be made into all kinds of oral health care products and oral medicaments used by conventional methods of preparing traditional Chinese medicine preparations. The products can significantly improve symptoms of osteoarthritis, and also can stabilize or even reverse the degradation of cartilage of osteoarthritis.