Objective To study the value of umbilical artery(UA)combined with fetal middle cerebral artery(MCA)for detecting fetal intrauterine hypoxia.Methods A total of 349 pregnant women undergoing childbirth in our hospital from February 2015 and February 2016 were divided into the observation group(fetal intrauterine hypoxia group)and control group(normal fetus group)according to the existence of fetal intrauterine hypoxia.Then the systolic peak velocity and end-diastolic velocity ratio(S/D),pulse index(PI),resistance index(RI),(S/D)MCA/(S/D)UA,PIMCA/PIUA,RIMCA/RIUA of UA and MCA were compared between the two groups.The sensitivity,specific degree and Youden index of each index for diagnosing fetal hypoxia were statistically analyzed.Results The S/D,PI and RI values of UA at 28-35+6 pregnant weeks and at 36-41 pregnant weeks in the observation group were higher than those in the control group(P＜0.05),while the S/D,PI,RI value of MCA and(S/D)MCA/(S/D)UA,PIMCA/PIUA and RIMCA/RIUA values were lower than those in the control group(P＜0.01).The resistance index corresponding ratios of MCA and UA for diagnosing fetal hypoxia had the highest Youden index.Conclusion The combined use of fetal UA and MCA resistance index ratios has higher clinical value for predicting fetus intrauterine hypoxia.