Abstract: The present invention provides a method that maintains chondrocyte phenotype during serial expansion by culturing a population of chondrocytes in a defined serum-free culture medium containing cytokines and on a substrate that is modified by covalent attachment of hyaluronic acid. The underlying principle is to maintain native chondrocyte phenotype by growing the dissociated chondrocytes on a substrate modified by covalent attachment of hyaluronic acid to retain native chondrocyte morphology and function. Chondrocyte expanded in this manner can be used in various medical applications to repair cartilaginous tissues that have been injured by trauma or disease. This substratum provides a microenvironment that more closely mimics that of native articular cartilage, thereby promoting chondrogenesis in a predictable manner.