The purpose of this research is to compare the effdct of the new weekly iron supplementation on maternal iron and zinc nutritional status with the effect of the present daily iron supplementation. To assess the iron ad zinc status of rpegant women visiting public health center in Ulsan, interview for dietary survey and general aspect of each subject was given and biochemical analysis of blood and urine was performed. The study subjects were divided to two groups randomly, but the subjects whose Hgb level was very low were allocated in daily group ethically because theeffect of weekly supplementation was not yet established as safety. Daily group received 80mg elemental Fe(250mg Fe as ferrous sulfate) per day for 100days, while weekly group received 160mg elemental Fe once a week for 15 weeks. After treatement, Hgb(p<0.01), Hct(p<0.01) , serum iron(p<0.05) and serum ferritin(p<0.001) in weekly group but RBC, Hgb , Hct , serum iron and serum iron and serum ferritin increased slightly. After correction for the initial Hgb by including it in the MANIVA, the difference in treatment effects of Hgb and TIBC between groups was statistically significant. The effect of weekly vs, daily iron supplementation program on zinc status was also studied. The difference in treatment effect between two groups was, however, not sifnificant. It is concluded that once weekly rion supplementation program in pregnant women was less effectgive to improve the iron status than daily iron supplementation program. However, because the weekly dose prevented a decline in Hgb as well as in ferritin, itw effect was positive , given the fact that non-supplemented women almost always exhibit a sifnificant drop in Hgb values. It seems that it will improve the iron status well if the amount or frequency of supplements is to be adjusted . Biweekly supplementation of a different dose or antother type of iron supplement, such as through a gastric delivery system, might be better.