ObjectiveTo review the mechanism and research progress of signal ing pathways which play key roles in the regulation of osteoblast differentiation and bone formation. MethodsRecent articles about signal ing pathways of osteoblast differentiation and bone formation were reviewed and comprehensively analyzed. ResultsAt present, multi ple signaling pathways have been found to be involved in the regulation of osteoblast differentiation and bone formation, among which bone morphogenetic protein-Smads, Wnt/β-catenin, Notch, Hedgehog, and fibroblast growth factor signaling pathways may play the most important roles. Not only each pathway has a complex regulatory mechanism itself, but also contacts and impacts with each other, thus they formed a more compl icated and sophisticated regulatory network, and regulate together osteoblast differentiation and bone formation. However, the mechanisms in detail of those pathways are still not very clear, because the animal experiment techniques are not yet mature as well as the relevant cl inical trials were carried out not too much. ConclusionThe complete molecular mechanism of osteoblast differentiation and bone formation should be further investigated, so as to lay a theory foundation for preventing and treating the common bone diseases in cl inical which are involve in osteoblast differentiation and bone formation.