回複：我有綠卡是否能辦收養？

If the ground of adoption is to bring him to USA as an immigrant, patience should be prepared.

You need to live with him for 3 year, assuming his parents have yet passed away. Then you may file petition for him, and let's say it is approved. He will need to wait another 10 years before applying visa.

BTW, your niece should remain single for eligibility all the time, otherwise you must be naturalized to be eligible.

http://blog.wenxuecity.com/blogview.php?date=200801&postID=6775#FB