Objective To study the Doppler ultrasound measurement of fetal middle cerebral artery peak ve -locity in the prediction of fetal thalassemia clinical value .Methods 90 cases of singleton pregnancies who were diag-nosesed for light or thalassemia intermedia patients ,also including her spouse were selected as the observation group , while in the same period in our hospital ,pregnant women of singleton pregnancy detected by Doppler ultrasound who had had no thalassemia gene ,also including her spouse were selected as control group .Gestation fetal brain hemody-namics related indicators of (22.0 ±3.0)weeks were analyzed for both groups .Results The thalassemia fetal middle cerebral artery peak velocity averaged (52.06 ±11.03)cm/s,compared with the control group ,the difference was sig-nificant(χ2 =348.20,P<0.01),but there were no significant differences in thalassemia fetus Pollex index ,resistance index and S/D(χ2=1.35,0.49,0.91,all P>0.05);Light with thalassemia intermedia fetal middle cerebral artery peak ve-locity had no significant difference compared with control group (χ2 =1.63, 5.79, P >0.05 ).Conclusion Doppler ultrasound used to detect fetal middle cerebral artery peak systolic velocity prediction thalassemia has the ad -vantages of valid,reliable,non-invasive,repeatable,which has broad application prospects .