Objective:To study the change characteristics of muscle mass,fat mass,moisture,basal metabolic rate,and bone mineral density of patients with colorectal cancer. Methods: 198 patients with colorectal cancer and 129 healthy persons were carried on the physical anthropology analysis using by body composition analyzer or bone mineral density instrument. Results: Weight,abdomen circumference,body mass index(BMI),systemic fat mass,trunk fat mass,and intracellular fluid,and bone density of patients with colorectal cancer were less than those in the control group (P < 0.05),while the extracellular fluid and basal metabolic rate were higher than those in the control group (P < 0.05). There were group differerces among the fat mass,intracellular fluid and extracellular fluid of patients with differrent pathological stage (P < 0.05). Conclusion: The changes of body composition in patients with colorectal cancerr were obvious,accompanying the decrease of fat,intracellular fluid and bone mineral density,while the increase of extracellular fluid and basal metabolic rate.