Obesity is the risk factor of cardiovascular disease， metabolic disease， orthopedics disease and other diseases. It has brought the heavy burden to the medical service and social economy. The application of Traditional Chinese Medicine (TCM) Constitution theory to guide obesity prevention is one of the hot spots now. But there are many different methods and standards to distinguish obesity. Then how to choose the appropriate index of obesity is a problem that the research of TCM constitution should resolve. To expound the relationship between obesity and the TCM constitution and the application of obesity index in the TCM constitution， analyse the advantages and disadvantages of different indicators of obesity and provide a reference for screening the favorable obesity index used in the research of TCM constitution is the main purpose of this paper.