Generally, human adipocytes can be broadly divided into white and brown fat cells. White fat cells are specialized to store chemical energy and brown adipocytes can produce heat under external stimulation. Recent studies have demonstrated that when mice are exposed to cold or receive β-adrenergic stimulation, some brown-fat-like cells may appear in the subcutaneous white adipose depot, and these cells are called "beige cells". Beige cells have the characteristics of both white and brown fat cells and can transfer to each other. Biologically brown fat in adult humans is similar to beige cells. This paper is to review the research progress on beige cells.