Abstract: To explore the effect of brassinosteroid（BR） on the expression of Rab15-like gene in the leaves and tillering nodes of winter wheat under low temperature stress, the cold-resistant winter wheat cultivar Dongnongdongmai-1 was used as the experimental material. The CDS sequence of Rab15-like gene was cloned by RT-PCR, and its basic physicochemical properties, secondary and tertiary structural characteristics, Rab15-like homologous proteins, and promoter cis-acting elements were analyzed by bioinformatics methods. Real-time fluorescent quantitative PCR（RT-q PCR） was used to detect the expression of Rab15-like gene in winter wheat under different temperature conditions after BR treatment. The results showed that the coding region sequence of Rab15-like gene was 1 265 bp,containing a 453 bp open reading frame encoding 150 amino acid sequences. Rab15-like protein belonged to the second major category of LEA family proteins, which was mainly distributed on the cell membrane and was a stable hydrophilic protein. RT-qPCR method was used to detect the effect of BR treatment on the expression of Rab15-like gene in tillering nodes and leaves of winter wheat under different temperature conditions. In the leaves, as the ambient temperature decreased, the expression of Rab15-like gene increased first and then decreased, reaching the highest level at-10 ℃. In the tillering nodes, the expression of Rab15-like gene continued to increase as the temperature decreased, and the expression level was the highest at-25 ℃. BR treatment could promote the expression of this gene in leaves under low temperature conditions, but had little effect on the expression of the gene in tillering nodes at 5, 0 and-10 ℃, but could significantly promote the expression of the gene at-25 ℃（P＜0.05）.In conclusion, the expression of Rab15-like gene was affected by temperature, indicating that Rab15-like gene might participate in the signaling pathway of winter wheat in response to low temperature stress.Exogenous BR treatment could promote the expression of this gene in winter wheat leaves and tillering nodes under low temperature conditions.