Abstract: Obesity is a complex chronic disease characterized by excessive intake of nutrients,excessive metabolism of the body,accumulation of fat in the body,and eventually overweight.Since the etiology of obesity is considered to berelated to environment,heredity,physiology,metabolism,behavior,psychology and so on,it is a result of the interaction between internal and external causes.Previous studies focused mainly on factors such as lack of exercise and excessive diet;however,recent studies have found that intestinal flora is also an important external cause of obesity.By changing the intestinal flora in the body,the environment in the body can be altered to improve obesity.This article reviews the recent study on the relationship between obesity and intestinal flora.