Time resolved MRA is valuable in study of cerebrovascular disorders. ASL based MRA permits visualization of blood flow without injection of contrast agent. Continuous labeling combined with zero TE readout features maximal labeling efficiency and high angiogram fidelity. However, the constant small flip angle excitation scheme limits its applicability in time resolved visualization. This work performed variable flip angle modulation to improve the quality of angiography in zTE-ASL MRA.