Objective To evaluate hemodynamics changes in patients with cerebral infarction of middle cere-bral artery(MCA)territory.Method Thirty five patients with acute cerebral infarction of MCA territory confirmed by MRI were selected to serve as patient group and thirty healthy persons were selected as controls.All subjects were measured by TCD.Results In patient group,the blood flow velocity of MCA in lesion side was lower than the other,the blood velocity ratios of MCA was lower than ratios in controls,there was a significant difference between the two groups;The ratios of anterior cerebral artery for lesion side to the other in patient group was higher than ratios in controls,there was a significant difference between the two groups;There was no significant difference for the ratios of posterior cerebral artery between the two groups;All pulsatility index of MCA in lesion side in patient group was decreased(P0.001).Conclusion TCD findings can partly reflect the collateral patterns in patients with MCA stenosis or occlusion.ACA was the primary collateral circulation in patients with cerebral infarc-tion of middle cerebral artery territory.