Applications of butylidenephthalide (BP), comprising the use of BP in providing a kit for promoting differentiation of stem cells into brown adipose cells, and the use of BP in preparing a medicament, wherein the medicament is used for inhibiting the accumulation of white adipose cells, promoting the conversion of white adipose cells into brown adipose cells, inhibiting weight gain and/or reducing the content of triglycerides, glucose, and total cholesterol in blood.