Abstract: Objective To approach a method for reducing the prevalence rates in pregnant women and infants.Methods 313 pregnant women with over 24 weeks pregnancy were divided into three groups:control group,not taking iron dextran;group QD,taking iron dextran once a day;group QW,taking iron dextran once a week.Six observation indices on the pregnant women are:hemoglobin(Hb),serum ferritin(SF),free erythrocyte protoporphyrin(FEP),red cell distribution width(RDW),mean corpuscular volum(MCV) and anemia prevalence rate.All the indices were measured once before and after observation respectively.Two observation indices on the infants are:hemoglobin(Hb) and anemia prevalence rate.Results The group's difference of the six indices before the observation over the three women groups is not significant.But the group's differenes of the six indices after the observation over the three women groups are significant.Of the three women's groups the group QD has the best curative effects.The group QD n the infanthas the highest mean of Hb among the three groups.The main factors effecting on the infanthb concentration are the pregnant women's Hb concentration after the observation and MCV concentration before the observation.Conclusion Taking iron dextran in middle and late pregnancy has significant effects on reducing the anemia prevalence rates in pregnant women and infants.