Objective Application of transcranial Doppler ultrasound (TCD) in evaluation of collateral circulation in patients with anterior cerebral artery dysplasia (Willis). Methods 31 cases of anterior cerebral artery (ACA) in patients with ACA dysplasia, hypoplasia of ipsilateral and contralateral thick side were divided into two groups, artery dysplasia detection side of the brain (MCA), ACA blood flow velocity, and the bulky side. At the same time through the compression of the ipsilateral carotid artery were observed with TCD MCA test, the peak systolic velocity of two groups after pressure (Vp) compensation rate, mean flow velocity (Vm) compensation rate and the end diastolic velocity (Vd) were compared respectively with the compensatory rate, two healthy adults were compared with each group corresponding compensation rate. Results The blood flow velocity of ACA in the dysplastic group was significantly lower than that in the thick side group (P<0.001). There was no significant difference in MCA, Vm, Vd and Vp in the ipsilateral side group (P=0.9072,0.7065,0.5676). The adverse side group MCA development pressure neck after Vp, Vm, Vd compensation rates were (0.46±0.11), (0.50±0.11), (0.55±0.11), bulky side groups compensatory rate were (0.43±0.14), (0.48±0.15), (0.53±0.17), the two groups have no significant difference(P=0.3519, 0.5517, 0.5844). Healthy normal group MCA Vp, Vm Vd, compensatory rate were (0.47±0.12), (0.52±0.13), (0.58±0.15), two groups of Vp, Vm, Vd respectively compared with healthy normal compensatory group had no significant difference (P=0.6805, 0.4405, 0.3054 and 0.1224, 0.1523, 0.1193). Conclusion TCD can be used to evaluate the compensatory effect of intracranial arteries in patients with ACA dysplasia in real time, and there is no significant difference between the affected side and the contralateral side.