It is necessary to compare the dietary characteristics among different age groups because different nutritional problems require different dietary applications. This study was performed to identify the nutritional characteristics of Korean diet among different age groups. The study subjects consisted of preschool children(PC), elementary school children(EC), high school students(HS), college students(CS), and adults over 30 years old living in Seoul and the surrounding areas. The subjects over 30 years old were classified to 30-49 years, 50-69 years, and over 70 years. A dietary survey was conducted using 24-hour recall method and data were collected from 2392 subjects. Energy intake was as much as 1771kcal for PC, 2139kcal for EC, 2475kcal for HS, 2276kcal for CS, 1860kcal for 30-49 years, 1715kcal for 50-69 years, 1326kcal for over 70 years. The subjects of PC, EC, HS, and CS groups got about 25% of energy from fat, but the subjects in 30-49 years, 16%, those in 50-69 years, 15%, and those over 70 years, 13%. The energy consumption from protein was about 15% in each age group. Percent of energy intake as Korean RDA was greater than 100% for PC, EC, HS, and male CS groups. The percent intake for RDA of calcium, iron, vitamin A, and vitamin B$_2$was low in most age group. Iron intake was inadequate in female of PC and CS groups, and subjects in 30-49 years and over 70 years. Mean adequacy ratio(MAR) was 0.9 in PC, and decreased with increase of age. Therefore MAR did not reach to 0.7 among subjects over 70 years. Index of nutritional quality(INQ) for calcium, iron, vitamin A, and vitamin B was below 1 in most age groups. From these results, major nutritional problems of each age group were overall inadequate intakes of calcium and iron, excess consumption of protein and fat for PC, EC, HS, and CS groups, and inadequate nutrients intake of subjects over 70 years old. According to these results, each age group seems to need specific nutritional intervention. (Korean J Nutrition 34(5) : 554~567, 2001)