This study was performed fir the purpose of finding the relationship between fat-free mass (FFM) which mainly represents muscle mass change, and muscle strength. The correlation between diet and exercise behaviors and FFM in healthy elderly men over age 55 was also investigated. FFM and corresponding hand grip strength declined significantly with increasing age. However the concentration of serum albumin, the indicator of protein nutritional status, showed no change with increases in age. The subjects were categorized into three groups according to FFM textiles. Anthropometry such as height, BMI, circumferences of waist and hips, body fat mass percent and hand grip strength decreased significantly in the lowest FFM group. But albumin level showed no change relative to FFM level. FFM showed a significant relationship to nutrient intake such as energy and fat. However, no association was found with exercise behavior probably because there were no instances of resistance exercise habits among the subjects studied. The variance in FFM could be attributed 86.2% to height and age. The variance of height-adjusted FFM could be attributed only 40.6% to age and fat intake. In conclusion decreases in FFM may cause reductions in muscle strength in elderly men. Increasing energy and fat intake were associated with increased FFM and may protect elderly men from the risk of sarcopenia. FFM had no association with endurance exercise habits.