Objective To investigate the post-UCO ( unilateral carotid occlusion) ischemic symptoms and possible correlations of anterior and posterior communicating arteries ( ACoA and PCoA) patterns of the circle of Willis between parents and their progeny in gerbils and to selectively breed an ischemia-prone gerbil group． Methods We used 398 gerbils from five generations to develop focal cerebral ischemia after UCO，and compared the UCO ischemic symptoms and possible correlations of ACoA and PCoA patterns between parents and their progeny． The progeny which are from the parents with incomplete Willis circle were mated to selectively breed an ischemia-prone group． Results It was shown that if the parents had complete ACoAs，their progeny also had a complete ACoAs，and there were significant differences when the parents’ACoAs were incomplete: in 60. 4% of offsprings the type of ACoA was consistent with that of their mother and in 48. 2% consistent with that of their father． After selectively breeding for five generations，the proportion of UCO ischemia increased from 40% in the F1 animals to 75% in the F5 animals． Conclusions Variations in the circle of Willis are of genetic nature and we have successfully established an ischemia-prone gerbil group．