in memory of
keeping alive the memory（为）纪念
They are going to erect a monument in memory of the men who laid down their lives in defense of their country．他们将树碑纪念为保卫祖国而献身的人们。
A monument has been erected in memory of their beloved teacher．为了纪念他们敬爱的老师，他们已经树起了一块纪念碑。