回複：為了搞清父母做dependent的問題，我好好查了IRS文件，詳情在內

I suggest you to call the IRS. I called IRS two times for my child. It is very helpful. I also looked the Tax manual. It seems that if you are a resident (at least have green card) and your paraents in USA more than 183 days, then it is possible to claim them as your dependents. But please call the IRS.