China does not recognise dual nationality

The Nationality Law is short and it is not ambiguous. There is no registration to make and no declaration to sign: naturalising elsewhere ends Chinese nationality by operation of law. That has consequences that surface years later, usually at a border.

What follows from it

Permanent residence, which is a different thing

China does issue a permanent residence card to foreign nationals, sometimes called the Chinese green card. It is residence, not nationality, and it does not conflict with holding a foreign passport. The family of a holder is eligible for a Q visa on the same footing as the family of a Chinese citizen.

 Using a Chinese passport after naturalising elsewhere is not a grey area.  The nationality ended when the other one began, and travelling on a document that is no longer valid is a problem that lands at the port of entry rather than at a consular counter.

What the law actually says

Two articles do the work. One provides that a Chinese national who has settled abroad and voluntarily acquires another nationality loses Chinese nationality.

The other provides that a child born abroad to Chinese parents who had themselves settled abroad, and who acquires a foreign nationality at birth, does not have Chinese nationality.

Everything else in this area follows from those two sentences, including why one American-born child of Chinese parents needs a visa and another needs a travel document.

All the proceduresFees and documents