Objective:To explore circadian pattern of β-klotho and regulation function of core circadian gene BMAL1. Methods:The circadian expression patterns of β-klotho in cell level and liver tissue of mouse were detected by Real-time PCR .Plasmids expressed BMAL1 and CLOCK were prepared,then transfected into HepG2 cells to analyze β-klotho expression level by RT-PCR method. Furthermore,the expression level of β-klotho in the BMAL1 knockout mice was also detected. Results:β-klotho displays a robust circadian expression pattern. At the molecular level,core clock elements BMAL1 and CLOCK coordinately activate β-klotho transcription. Conclusion:β-klotho is a new clock-controlled gene.