Arthritis of major joints especially osteoarthritis of the knee is a very frequent disease of human beings mainly in the developed countries, the major pathological changes occur in the structure of hyaline cartilage. Differential scanning calorimetry (DSC) is a well established method for the demonstration of thermal consequences of local and global conformational changes in biological systems. It has never been applied for the investigation of cartilage. According to the present study the thermograms may prove and follow the changes in the structure of cartilage in different stages of osteoarthritis. The differences were clearly demonstrated between;he various anatomical origins of the cartilage as well as intact and osteoarthritic samples with the changes in total enthalpy and heat capacity, as well as by the shape of DSC scans themselves.