rén bù kě mào xiàng
you can't judge a person by appearance (idiom)
you can't judge a book by its cover; often in combination 人不可貌相,海水不可斗量[ren2 bu4 ke3 mao4 xiang4 , hai3 shui3 bu4 ke3 dou3 liang2]
人
rén
person; people
不
bù
no; not so
可
kě
(prefix) can; may; able to; -able
貌
mào
(bound form) appearance; looks; outward form
相
xiàng
appearance