Carotid blood flow was measured with a ultrasonic volume flow meter in 38 infants. The carotid blood flow was 1.50±0.55 ml/sec. At the same time peak systolic flow velocity, mean blood velocity, end diastolic velocity, pulsatility index (PI) and resistance index (RI) in the middle and anterior cerebral arteries were measured by duplex Doppler scanning. There was a correlation between the carotid blood flow and the mean blood velocity in middle and anterior cerebral arteries. However, PI and RI were not well correlated with carotid bood flow.