Objective To explore hemoglobin level and its changes in premature infants under corrected age of 24 months,and to provide guidance on early detection for anemia in premature infants. Method Totally 461 eligible premature infants were offered early comprehensive intervention and regularly followed up. The hemoglobin content was measured at corrected age of 1,3,6,12 and 24 months. The changes of hemoglobin level in premature infants were analyzed by using the multilevel model. Results The average content of hemoglobin in premature infants was the lowest at corrected age of 1 month,and then increased with the infants getting older,and the average content of hemoglobin at corrected age of 10 months was the same as that in full-term infants. Multilevel model results showed that the average hemoglobin content of premature infants at corrected age of 1 month was 109.40 g/L,with instantaneous rate of change of 2.05 points,while the growth rate gradually decreased. The hemoglobin content at corrected age of 1 month was different among individuals,while the rate of growth of hemoglobin content did not find any differences between individuals. Gender,birth gestational age and birth weight were not found to have effect on the hemoglobin content at corrected age of 1 month in premature infants (P>0.05). Conclusions The initial value of hemoglobin in premature infants is different,but the rate of growth is the same. Early comprehensive intervention has positive effect on maintaining hemoglobin levels in premature infants. And the hemoglobin levels of premature infants should be monitored regularly.