[jbg_]

I know several people that are dual citizens of China and US. China doesn't recognise the second citizenship, but that doesn't prevent you having it. If China finds out, though, they'll apparently strip you of your Chinese citizenship.

[yegle]

Travel between US/CN will be a hassle for those people because the border control officials of China won't let you board the flight if you show your CN passport doesn't have US visa. One loophole is that you can use Hong Kong as the middle hop since you don't need passport to visit HK.

The dual citizen status is actually very common. If a child's parents are Chinese citizen working/studying in US with a temporary visa (H1b, F1) and the child was born in US, the child is eligible to be a Chinese citizen, thus a dual citizenship.

[wingerlang]

I believe they will force you to pick one of the two.