This study investigate the balance and biochemical status of riboflavin in Korean men. During the experimental period, four riboflavin diets with different levels of riboflavin(0.4, 0.6,0.8 and 1.0mg/1000kcal) were followed by eight healthy college men. the riboflavin status was assayed by erythrocyte glutathine reudcctase activity coefficient (EGRAC0 and urinary excretion of riboflavin. Riboflavin intake of the subjects who consumed a det was 0.46mg/1000kcal. the riboflavin intakes of the subjects who consumed the experimental diet with 0.4, 0.6, 0.8 and 1,0mg/1000kcal of riboflavin were 0.41, 0.60, 0.81 , 0.97mg, respectively. Fecal riboflavin loss, absorbed riboflavin , urinary riboflavin loss and retained riboflavin increased in the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin. The average EGRAC values for the subjects consumed 0.4, 0.6, 0.8 and 1.0mg/1000kcal of riboflavin were 1.303$pm$0.029, 1.271$pm$0.022, 1.239$pm$0.013, 1.202$pm$0.030, respectively and urinary riboflavin values ($mu extrm{g}$/g creatinine) were 86.89$pm$ 20.07, 123.88$pm$ 15.88, 240.70$pm$57.14 and 393.36$pm$76.94, respectively. Results indicate that 0.6mg/1000kcal is the level of riboflavin intake needed to maintain urinary riboflavin within the normal range. And above1.0mg/1000kcal of riboflavin is need to maintain urinary riboflavin with in the normal range. And above 1.0mg/1000 of riboflavin is needed to maintain the EGRAC within the normal range. The riboflavin intake correlated positively with urinary riboflavin value, but correlated negatively with the EGRAC value. The EGRAC value correlated negatively to protein intake as well as animal protein intake. The linear equation of between riboflavin intake and EGRAc was EGRA=-0.1667 $ imes$riboflavin intake +1.3710. The riboflavin intake to maintain EGRAc below 1.20 was calculated 1.02mg/1000kcal by the above equation.