Abstract: Leptin is the expression product of obese gene （ob gene）. Leptin is secreted by adipocytes and combined with hypothalamic leptin receptor so as to inhibit appetite centers and decrease food intake, furthermore it could improve lipolysis and increase heat production by exciting nervous system so as to decrease body weight and increase lean meat percentage. The biological function of leptin and the regulatory effect on fat deposition were summarized in order to provide theoretical basis for regulating the quality of livestock and poultry meat and producing high-quality livestock and poultry products.