目的：研究椎动脉发育不良的磁共振血管造影分型及临床意义。方法对80例椎动脉发育不良患者的磁共振血管造影检查结果进行分型，分析不同分型与后循环短暂性脑缺血发作及脑梗死的相关性。结果椎动脉发育不良根据磁共振血管造影表现分为Ⅳ型，其中Ⅰ型后循环短暂性脑缺血发作发生率为81．8％、脑梗死发生率为9．1％，Ⅱ型分别为75．0％、17．9％，Ⅲ型分别为62．5％、29．2％，Ⅳ型分别为35．3％、58．8％；不同分型患者后循环短暂性脑缺血发作及脑梗死的发生率比较差异有显著或极显著性（χ2＝33．57、11．21，P＜0．05或0．01）。结论根据磁共振血管造影影像学表现，可将椎动脉发育不良分为Ⅳ型；椎动脉发育不良分型越高，发生脑梗死的概率越高。、Objective To study the typing and clinical significance of magnetic resonance angiography (MRA) in vertebral artery dysplasia (VAD) .Methods MRA results of 80 VAD patients were classified and the correlations between different typing and posterior circulation ischemia (PCI) or cerebral infarction analyzed .Results According to MRA features the VAD were classified as 4 types ,the PCI and cerebral infarction incidence were respectively 81 .8% and 9 .1% in TypeⅠ ,75 .0% and 17 .9% in Ⅱ ,62 .5% and 29 .25 in Ⅲ ,35 .3% and 58 .8% in Ⅳ ;there were significant or very significant differences in the PCI and cerebral infarction incidences among different VAD types (χ2 =33 .57 ,11 .21;P<0 .05 or 0 .01) .Conclu‐sion According to MRA features the VAD were classified as 4 types;the higher the VAD typing ,the higher the incidence of cerebral infarction .