The transforming growth factor b (TGF-b) superfamily is composed of TGF-b subfamily and bone morphogenetic protein (BMP) subfamily. The ligands, ligand antagonists, receptors and intracellular transductors that engage in the TGF-b superfamily signaling pathway play their unique roles during endochondral ossification via regulating the lineage differentiation, proliferation, maturation, apoptosis and mineralization of chondrocytes. BMP signaling dominates chondro-genesis through initiating the chondrocytic commitment of mesenchymal cells and maintaining the chondrocytic phenotype. During the development of growth plate, BMP signaling promotes the maturation of chondrocytes to facilitate ossification, whereas TGF-b signaling inhibits the hypertrophic differentiation to preserve adequate chondrocytes within the growth plate. Both TGF-b signaling and BMP signaling are indispensable for the maintenance and repair of articular cartilage. Therefore, it indicates that TGF-b superfamily may function essentially all throughout the development of skeletons.