OBJECTIVE To provide the evidence for more accurately assessing the patient's body composition, predicting exercise capacity and guiding rehabilitation exercise by analyzing the body compositions in patients with coronary heart disease, and to study the correlation between body compositions and exercise capacity. METHODS The study enrolled 663 patients with coronary heart disease in NYHA I-II stages, who underwent coronary intervention therapy between December 2013 and August 2014. Between 15th and 20th days of the onset, cardiopulmonary exercising testing (CPET, Bruce Protocol) was conducted, and the body composition was measured with the Inboby720 body composition analyzer before CPET. RESULTS All the patients completed the body composition evaluation and the CPET. According to the three indicators of body mass index (BMI), percentage of body fat (PBF), waist-hip ratio (WHR), the diagnostic rate of obesity was 22.8%, 63.3%, and 72.7%, respectively. There was a good negative correlation between PBF and exercise capacity (r=-0.306, P<0.001). Compared with non-obesity patients, the exercise capacity of obesity group decreased according to PBF (P<0.01). The patients were divided into low, moderate and high exercise capacity groups according to METs, and the difference was only the PBF among the three groups (P<0.05). CONCLUSIONS PBF, measured by body composition, is a more accurate diagnosis of obesity and has a good negative correlation with exercise capacity, which can be used as an important indicator to predict the exercise capacity in patients with coronary heart disease and guide the rehabilitation exercise.