沧海桑田（滄海桑田）　

◎ 沧海桑田 cānghǎi-sāngtián

[the swift changes of the world;great changes are seen in the course of time;the evanescence of the worldly affairs is like the sea turned into a mulberry field (orchid)] 大海变成了种桑树的田地,种桑树的田地变成了大海。比喻世事多变,人生无常;或喻世事变化的巨大迅速——略称沧桑

山河改转,沧海桑田