回複：請問我父母這種情況是否會被移民官認定有移民傾向?

Your case is ok. You may write a letter to VO and state that your parents visited Canada while you lived there and they returned before their visa expired and they will do the same ... if they come to visit USA.

If you have gone back China to see your parents between now and their last visit, that will also help. Make clear that you would like to show your parents around in USA (in your invitation letter).

There should be no concern about their extension in Canada, the fact is that they did not stay illegally. If they were asked the reason for extension just tell the truth.

Good luck!