PROBLEM TO BE SOLVED: To provide a differentiation-inducing promoter and a differentiation-inducing method, for efficiently and selectively making a differentiation induction from stem cells to brown adipose cells.SOLUTION: The differentiation-inducing promoter from stem cells to brown adipose cells is provided, with Gdf (growth differentiation factor) as an active ingredient. The differentiation-inducing method for such brown adipose cells is also provided, including culturing cells in the presence of Gdf. This invention is also applicable to prevention and/or amelioration of diabetes, metabolic syndrome and/or obesity.