Ten healthy wome 2-~25 years participated in a 5-week metabolic study to investigate the daily riboflavin requirement of Korean women. Three daily menu and meal patterns were used. Low riboflavin(LR) diet provided riboflavin at a level of 0.71mg / 1000Kcal based on food composition table. High riboflavin(HR) diet provided 1.14mg / 1000Kcal. The riboflavin status was assessed by erythrocyte glutathione reductase activity coefficient(EGRAC) and urinary exretion of riboflavin. Mean EGRAC of LR period and HR period were 1.17+0.08 and 1.01+0.03, repectively. There were discrepanices of riboflavin content of experimental diet between chemical analysis and calculation by Korean food composition table. Urinary riboflavin excretion of subjects was acceptable over the whole study period. It appeared that 0.71mg / 1000Kcal is requirement of riboflavin to maintain EGRAC withing normal range. Thus, it is suggested that current recommendation of 0.6mg / 1000Kcal of riboflavin intake may not be adequate as RDA level in Korea.