回复：非常谢谢863211。问题是孩子是才合法领养的。父母绿卡已经3年半了。

这种情况能申请follow-to-join to file I485吗？
-No if the adoption occurred after you got the green card. You can file I-130 for the kid now, but the kid can not file I-485 until the priority date is current which normally takes five years and thus, your kid can not get the green card within US.

But, one solution is that your can file I-130 for the kid now, and then at least one of the parents gets the US citizenship later, then upgrade the I-130 from F2A to Immediate Relative of US citizen. Thus, the kid can file the I-485 within US. In this case, the kid does not need to go back to China and just wait for the parent to get the US citizenship to file the I-485. The kid's unlawful presence does not affect his/her I-485 filing and approval as the Immediate Relative of a US citizen no matter how long the kid illegally stays in US.