中文摘要：

本文将乙型脑炎病毒（Japanese encephalitis virus，JEV）基因I型HEN0701株在BHK-21细胞上传代，并通过空斑纯化和接种小鼠来筛选弱毒株。通过空斑试验和-步生长曲线，比较弱毒株和其亲本强毒株的生长特性。结果显示，JEvHEN0701株经过在BHK。21细胞上传代100代和10轮空斑纯化，挑选获得6株克隆株。将6株克隆株经脑内和皮下接种小鼠，筛选获得一株致弱株10S3。与HEN0701相比，10S3的空斑形态比较一致；而生长曲线显示，HEN0701在BHK．21上生长速度比10S3快。

英文摘要：

The genotype I （GI） strain HEN0701 of Japanese encephalitis virus was serially passaged up to 100 times and plaque cloned 10 times in BHK-21 cells. The attenuated strain 10S3 was identified via pathogenecity tests in mice. With a little difference in plaque size, the 10S3 strain showed more uniform plaque morphology than its parent HEN0701. The growth kinetic of the 10S3 strain was different from that of HEN0701.