1. Nutritional conditions have improved remarkably for the past 40 years in Japan; major improvements are increases in protein intake (69.7 in 1955 to 79.2g/day per capita in '88), and fat intake (20.3 in '55 to 58.3 g/day per capita in '88), both of which are significantly related statistically to the gradual reduction of stroke mortality (r = -0.74, not significant; r = -0.78, p < 0.05) and to a remarkable extension of average life span (r = 0.91, p < 0.01; r = 0.98, p < 0.001) in the Japanese. 2. Average heights of 12-year old male and female children, correlating significantly with these nutritional improvements, are significantly positively correlated with average life spans (men and women respectively; r = 0.97, p < 0.001). 3. Thus, general nutritional improvements among the Japanese are regarded as the major contributory factor to the recent achievement of top-ranked position for longevity in the world.