防微杜漸（防微杜漸）　

◎ 防微杜漸 fángwēi-dùjiàn

[arrest what seems to be the begining of an unwholesome trend;check erronrous ideas at the outset] 當(dāng)壞事、壞思想、壞作風(fēng)剛剛冒頭的時候,就加以制止,不讓它發(fā)展下去