Abstract：Kaschin-Beck disease is a kind of endemic osteoarthritis disease, and Zamgtang County is one of the serious areas of Kaschin-Beck disease. An investigation and analysis of water source and water quality of Zamgtang County have led the authors to believe that the low degree of mineralization and high humic acid in drinking water are two key environmental pathogenic factors for Kaschin-Beck disease in that area. Low degree of mineralization results in the lack of nutrient elements necessary for cartilage tissue, and high humic acid damages cartilage cell. In view of this, water improvement demonstration projects exploiting the small-scale deep groundwater have been put into practice. These projects are suitable for the Kaschin-Beck disease area and will cut off pathogenic factors.