Objective To assess the efficacy and the optimum dose of recombinant human ery- thropoietin(rhEpo) in the treatment of the anemia of premature.Methods 40 preterm infants with less than 35 weeks of gestational age and less than 2000gin of birth weight were randomly assigned to receive subcutaneous rhEpo 150U?kg~(-1)?t~(-1)(n=10) 250U?kg~(-1)?t~(-1)(n=15),three times weekly for 6 weeks,or no treatment(control,n=15).Results Postnatal decline of hemoglobin(Hb) and hematocrit (Hct) were lessened in the treated groups,particularly in the rhEpo 250U?kg~(-1)?t~(-1)group; and there were significant differences in each groups by analysis of variance(all P0.05).Serum iron dropped,more significantly in the treated groups than in control group (all P0.05).After treatment,serum levels of erythropoietin was higher in rhEpo 250U?kg~(-1), t~(-1) group than in both rhEpo 150U?kg~(-1)?t~(-1) and control groups (P0.05).No side effects related to rhEpo therapy were observed.Conclusious RhEpo therapy for premature infants is effective and dose-dependent.Therapy is more efficient when given in high dose.It can reduce or replace the need for blood transfusion.