Protein is the body of essential nutrients, mainly made of a complex compound consisting of carbon, hydrogen, oxygen, nitrogen and sulfur, phosphorus, iron, iodine, copper and other inorganic elements. The basic unit of a protein, such as amine groups can be synthesized, but there are also a part of the human body can't synthesized and must be ingested through foods. Proteins, involved in muscle growth, metabolism and repair, are essential nutrients for the human body. However, it is not the major energy source for the body but the main components of muscle and tissue which play important roles for physiological and functional activities. Recently, there are many studies focused on body composition which could be applied to evaluate the health status, physical fitness, and exercise performance. The previous reports tried to figure out the effects of exercise and nutrition on body composition and the results showed the intake of high proportion protein could directly alter the body composition. In additions, the high protein diet was also used for weight management due to physiological effects, such like satiety increase, thermogenesis enhancement, and energy expenditure efficiency. Therefore, the high protein diet exhibited regulatory role on body composition and it is an important issues for proper diet management, fat percentage maintenance, and health promotion. This paper will review the impacts of high protein diet on body composition.