We analyzed the blood cell counts and serum levels of total protein (TP), total cholesterol (TC) and triglyceride (TG) of 2,231 healthy subjects (1,295 men and 936 women) between age 20 and 99 years in order to clarify the following two subjects. (1) In the approximately 10 years since the report of Shirakura et al in 1978, eating habits have improved and the average life expectancy has extended in Japan. Is there any effect of such betterment on blood cell counts of the aged? (2) It has been pointed out that quality of everyday life, such as staying at home but not in an old-age home, working, traveling, and so forth, had an influence on the blood cell counts of aged. Is there any difference between the blood cell counts of people under 60 years and those of people older than 60 years who have a good quality of life as mentioned above? The hemoglobin concentration, red blood cell count, and hematocrit value began to decrease in men in their sixth decade and in women in their seventh decade and the change was more prominent with advancing age, especially in men. The white blood cell count and platelet count tended to decrease with advancing age. The serum levels of TP, TC, and TG also declined with age in those over 60 years of age. These results confirmed that the hemoglobin concentration, red blood cell count, and hematocrit value decrease in the elderly subjects as they grow older and it may be considered that reduced ingestion of protein is one of the causes of the phenomenon.