This study was performed to investigate the effect of sources of protein on iron bioavailability in 10 healthy young Korean women. The 18-day metabolic study consisted of a 6-day adaptation period, 6-day moderate protein(60g protein/day, 18mg Fe/day) and 6-day high protein period(90g protein/day, 18mg Fe/day). During the moderate and high protein period, 5 subjects were fed the high plant protein meals(80% plant protein). Fecal excretion of dietary iron was significantly higher(p<0.05) in high protein high plant diet group(HPP, 9.48$pm$1.61mg/day) than in high protein high animal diet group (HPA, 14.40$pm$0.89mg/day). Apparent absorption and bioavailability of iron was also significantly higher(p<0.10) in HPA(40.7$pm$5.3%, 6.46$pm$1.61mg/day) than in HPP(14.4$pm$5.3%, 2.39$pm$0.89mg/day). But there was no significant difference between the high animal protein group and high plant protein group in moderate protein period. Serum iron concentration and transferrin saturation increased as animal protein intake increased, from 106.0$pm$5.1ug/이 and 30.6$pm$1.5% for MPA to 129.1$pm$6.7ug/이 and 37.1$pm$1.3% for HPA. Statistically positive correlations were shown not only between the level of dietary heme iron and apparent absorption(r=0.95, p<0.05), but also between serum iron concentration and apparent absorption(r=0.64, p<0.05). Negative iron balance was shown in two subjects fed the moderate protein meals. These results suggest that recommanded dietary allowances of iron may be under the need to maintain the positive balance, and iron bioavaliability increase by only high level of animal protein intake.