Brown adipose tissue is a kind of special fat that “consumes energy” in mammalian body. Through uncoupling UCP1（uncoupling protein 1） located on the inner membrane of mitochondria， it can promote glycolipid metabolism and improve energy balance. Although the functional characteristics of brown fat have been deeply studied in the treatment of metabolic diseases， the research on the effect of brown fat on meat quality is still in the initial stage. In this paper， the origin， functional characteristics and activating factors of brown fat differentiation were reviewed， and the relationship between brown fat and intramuscular fat， fatty acid composition and lean meat rate of livestock was expounded， which could provide scientific reference for raising and regulating livestock growth and improving meat quality.