Abstract: Obesity has become an important problem that seriously endangers human health, which is closely related to cardiovascular diseases, metabolic diseases, and malignant tumors. The most commonly used indicators to assess obesity are body mass index, waist circumference, waist-to-hip ratio and so on. However, with the in-depth research on the pathogenesis of obesity, different parts and types of adipose tissue can be distinguished. There are two types of adipose tissue in the human body: white adipose tissue (WAT) and brown adipose tissue (BAT). Excessive accumulation of WAT is characteristic of obesity, while BAT is less active in obese individuals. ¹⁸F-FDG PET/CT can simultaneously acquire the volume and metabolism of different parts and types of adipose tissue. The authors review the application and progress of ¹⁸F-FDG PET/CT in obesity from the perspective of different adipose depots.