Objective To explore the effect of umbilical cord milking on related indexes of premature infants.Methods PubMed,Embase,The Cochrane Library,Web of Science,CNKI,WanFang Data,VIP,Sinomed were searched for randomized controlled trials about preterm infants’ umbilical cord milking published from inception to February 2019. Two trained evaluators screened literatures,evaluated quality and extracted data independently,and Meta-analysis was implemented with Review Manager 5.3 software.Results Nine articles(7 in English,2 in Chinese) were included in the analysis,which involved 388 cases of umbilical cord milking(UCM) and 386 cases of immediate cord clamping(ICC).The results of Meta-analysis showed that:①Compared with ICC,UCM could increase initial hemoglobin[SMD=0.75,95%CI(0.51,0.98),Z=6.22,P<0.01],systolic blood pressure[MD=3.85,95%CI(0.75,6.95),Z=2.44,P=0.01],diastolic blood pressure[MD=3.75,95%CI(1.20,6.31),Z=2.88,P<0.01] and blood flows in superior vena cava;②Compared with ICC,UCM could decrease the number of blood transfusions[RR=0.72,95%CI(0.54,0.95),Z=2.28,P=0.02],mechanical ventilation time[SMD=-0.31,95%CI(-0.57,-0.05),Z=2.38,P=0.02] and sepsis[RR=0.73,95%CI(0.57,0.94),Z=2.49,P=0.01];③There were no statistical differences in peak levels of bilirubin,numbers of preterm infants for phototherapy,incidences of polycythemia and intraventricular hemorrhage between two groups.Conclusion UCM improves the related indexes of preterm infants,reduces the need for blood transfusion,shortens the mechanical ventilation time,decreases the incidence of sepsis,and does not increase the risk of short-term adverse outcomes.