Bone metabolism⁃related diseases have become an increasing health burden worldwide and fur⁃ther basic research is still needed for a better understanding of the pathogenesis of these diseases and improvingand expanding existing prevention and treatment methods. Circadian circadian clock can regulate the physiologyand pathology of many organisms. In bones，circadian rhythms help coordinate bone formation and absorption.Bmal1 is the core biological clock gene，which plays an important role in the regulation of circadian rhythm，partic⁃ipates in the rhythm oscillation of bone formation and the expression of extracellular matrix. Chondrocytes，osteo⁃blasts and osteoclasts play an important role in the integrity and function of bone. The abnormal expression ofBmal1 would affect bone metabolism，and vice versa，bone metabolism would also affect the expression of Bmal1.