Articular cartilage is an important structure contributing to shock absorption and joint lubrication. Aging and trauma cause loss of function of articular cartilage, resulting in osteoarthritis(OA). Chondrocyte, the only type of the cell that resides in the articular cartilage. Recent studies have revealed that aging-associated changes in chondrocytes are important causative factors of OA. This review describes various mechanism and factors involved in aging of articular cartilage and chondrocytes.