Can I leave China after the US green card expires?

Hello, I'm glad to answer your question. You can't apply for a green card extension in China, so you need to apply for a green card again before entering the United States. Because it will be very troublesome to return to the United States with an expired green card, you may be refused entry or boarding. If you have no intention of permanent residence, but only return to the United States for a short time, you can go to the American consulate, return your expired green card to the consulate, formally give up your permanent residence status in the United States, and apply to the consulate for non-immigrant travel or other visas to go to the United States.