Objective:To investigate the role of mineralocorticoid receptor(MR)in regulating the function of mouse primary brown adipocyte. Methods:The primary brown adipocytes were separated from C57BL/5J mice and induced for differentiation. The expression of genes related to brown fat function, including uncoupling protein-1(UCP1), the cell death-inducing DNA fragmentation factor-α-like effector, domain- containing protein(CIDEA), peroxisome proliferator-activated receptor alpha(PGC1α) and fatty acid binding protein 4(FABP4) were observed in MR ligands(aldosterone), MR antagonist(spironolactone)and glucocorticoids(cortisone)treated cells, respectively. Results:Mineralocorticoid could significantly increase the expressions of UCP1,PGC1α and FABP4. Conversely, the expression of UCP1 was suppressed by MR antagonists. Moreover, MR regulated the brown adipocyte function with the interaction of glucocorticoid. Conclusion:MR plays an important role in the function of primary brown adipocyte.