Abstract: Objective To clarify the mechanism and functions in regulating plant growth and stress response of circadian clock genes in Betula platyphylla Suk. Method The sequences of BpLHY, BpTOC1 and BpGI were analyzed, and the structure and functions of coding proteins were predicted by bioinformatics method. The expression levels of BpLHY, BpTOC1 and BpGI were quantified using qRT-PCR. Result BpLHY, BpTOC1 and BpGI genes in B. platyphylla were 2 283bp, 1 623bp, and 3 507bp, encoding 760, 540, and 1 168 amino acids, respectively. The proteins encoded by these genes were hydrophobic, non-secreted transmembrane protein.BpTOC1 and BpLHY transcript levels were low during the daytime, but high at night. In contrast, BpGI expression was low during the daytime, and high at night and its highest expression levels increased by 29.28 times at 9:00 am. The expressions of BpLHY, BpTOC1 and BpGI increased by 105% to 2 390% in the abiotic stress of heavy metal cadmium, low temperature (4℃), salt (NaCl); SA and SNP induced the transcription levels of BpLHY, BpTOC1 genes reducing by 70.1% to 97.75% while the expression of BpGI increasing by 150% to 280%. Conclusion This study may provide some references for further study of BpLHY, BpTOC1 and BpGI function in regulation of plant growth and stress response and the mechanism of circadian clock in B. platyphylla.