Objective To study anomalous types of vertebral artery examined by multi-slice spiral computed tomography angiography(MSCTA) and its clinical significance． Methods MSCTA data from 66 patients with anomalous vertebral artery were retrospectively analyzed． Results Three cases had simple origin variation. Fourteen cases (16 branches) had simple course variation (bended into the C5，C4 foramen transversarium). Both origin and course variations of vertebral artery were seen in 29 cases (34 branches). Two cases had unilateral vertebral artery with double branches. Eleven cases had vertebral arterial fenestration．There were 7 cases of basilar artery formed by unilateral vertebral artery. There was no statistic significance in atherosclerosis between the variation group and the control group（EM>χ/EM>SUP>2/SUP>=2.735,EM> P/EM>=0.098）. Conclusion MSCTA is a valuable noninvasive imaging method for the diagnosis o