Objective：This study aims to investigate the role and mechanism of macrophage scavenger receptor 1（MSR1）in the process of white adipose thermogenesis induced by cold exposure. Methods：The expression of MSR1 and markers of the thermogenic capacity of adipose（UCP1，Cidea，Cox8b）in subcutaneous white adipose tissue（scWAT）and brown adipose tissue（BAT）of wild type mice（MSR1 ^+/+）and MSR1 knockout mice（MSR1^-/-）fed with common diet（CD）were detected by qRT - PCR，Western blot and immunohistochemistry after 1 or 14 days of cold exposure. The polarization of macrophages in scWAT of MSR1^+/+ and MSR1^-/- mice fed with CD after 30 days of cold exposure were detected by qRT-PCR and flow cytometry. Obese mouse model was established by high fat diet（HFD），the weight changes were monitored in MSR1^+/+ and MSR1^-/- mice fed with CD or HFD for 12 weeks，and the metabolic cage method was used to monitor the changes of O₂ consumption and heat production. The expression of thermogenic genes in scWAT and BAT of mice fed with HFD for 12 weeks were detected by qRT-PCR and immunohistochemistry after 7 days of cold exposure. In vitro， macrophage conditioned medium was used to stimulate the differentiation of mouse preadipocytes，and the expression of thermogenic genes of mature adipocytes were detected by qRT-PCR. Results：Compared with MSR1^+/+ mice，the expression of thermogenic genes in adipose tissue of MSR1^-/- mice was significantly decreased. Further，the number of M2 macrophages in scWAT of MSR1^-/- mice decreased significantly. After fed with HFD for 12 weeks，MSR1^-/- mice had significantly higher weight，lower O₂ consumption and heat production. The thermogenic capacity of adipose tissue in MSR1^-/- HFD mice was significantly reduced compared with MSR1 ^+/+ HFD mice after cold exposure. In vitro cell studies，compared with the mature adipocytes induced by peritoneal macrophage conditioned medium in MSR1 ^+/+ mice，the expression of thermogenic genes in mature adipocytes induced by peritoneal macrophage conditioned medium in MSR1^-/- mice was significantly reduced. Conclusion：After cold exposure，MSR1 increases the thermogenic capacity of adipose tissue by promoting the polarization of M2 macrophages.