This study was performed to determine the effect of social class distribution as measured by lower social class rate on all cause and cause specific mortality in Korea. I obtained data on social class, fiscal autonomy of municipalities, number of medical doctors, region(Si/Gun) from 1955 Korea Census Data and Regional Statistics Data. And all of the data on mortality adjusted for age for 1995 for each district from the National Statistics Office. Lower social class rate ranged from 18.9％ for Kangnam gu to 85.7％ for Imsil gun and age standardized mortality ranged from 385/100,000 population for Kangnam go to 803/100,000 population for Sinan gun. Lower social class showed had a significant correlation with total mortality adjusted for age(r=0.81, p<0.0001). The association of the rate to total mortality remained highly significant after adjusted for number of medical doctors per 1,000 population, fiscal autonomy of municipalities and region(p<0.0001). Effects of the lower social class were also found for neoplasm (p=0.0008)； cardiovascular disease (p<0.0001)； infectious disease(p=0.0115)； respiratory disease(p=0.0085)； gastrointestinal disease(p<0.0001)； accident ＆ poisoning (p<0.0001). The findings suggest that policies that deal with the inequality in social class may have an important impact on the health of the population.