This study used a cluster random sampling method to measure the body fat mass of 1036 elderly people over 60 years old in Nanyang area using bioelectrical impedance method. The simple intelligence state examination scale was used to evaluate cognitive function, and the distribution of total body and local fat mass in the elderly were statistically analyzed to explore the relationship between body fat mass and cognitive impairment.The results showed that the total body fat, visceral fat, trunk fat, upper limbs fat and lower limbs fat mass of the elderly women in Nanyang area was higher than that of the men (P<0.05). In terms of total body fat, visceral fat, and trunk fat mass, urban males had higher values than rural males, and rural females had higher fat mass than urban females (P<0.05), while no such change was observed in fat mass in upper and lower limbs. Both cross-sectional and longitudinal follow-up studies showed that the total body fat, visceral fat and trunk fat mass decreased with age in males (P<0.05), while no such change was observed in other indexes. Similarly, with the increase of age, there was no statistical difference in the change of total body fat, subcutaneous fat, visceral fat, trunk fat and limb fat mass in females. The incidence of cognitive impairment was 19.47% in males and 28.91% in females, both of which increased with age (P<0.05). The incidence of female cognitive impairment in rural areas was higher than that in urban areas (P<0.05). Total body fat, visceral fat and trunk fat in cognitive impairment group were higher than those in cognitive normal group (P<0.05). There was no significant difference in fat mass in upper and lower limbs between the cognitive impairment group and the cognitive normal group. Total body fat, visceral fat and trunk fat were correlated with Mini-mental state examination score of cognitive impairment in all groups (P<0.05). There was no correlation between upper and lower limb fat mass and MMSE score of cognitive impairment in all groups. On the whole, the total body fat, visceral fat and trunk fat of the elderly in Nanyang area has a large gender difference, age difference and urban and rural difference, and has a close correlation with cognitive impairment. The incidence of cognitive impairment is higher in the group over 80 years old and the group of rural women. Health assessment and prevention of related diseases should be strengthened.