To maintain Canadian PR, u need to be in Canada for 6 months (i think it need not be continuous) in a given year. For US gc, u need to be in US once in 6 months. So theoretically, u may be able to do it.
This text was posted on one of the immigration attorney\'s sites:16. Can I keep both the U.S. Green Card and Canadian Landed Immigrant status?
ANSWER: Yes, you can keep both...but you better have a good story!
Here\'s the problem: to keep your green card, you have to have the intent to reside permanently only in the United States. Canada requires a similar intent of it\'s landed immigrants. How can you intend to reside in both countries at once? If INS suspects that you no longer intend to reside permanently in the U.S., they can lift your green card. This usually happens during border crossings. The issue can also come up during naturalization: to become a U.S. citizen you must have intended to reside permanently in the U.S. continuously since the day you got your green card.
As a practical matter, you\'ll have some explaining to do at the border if INS finds out you hold residency in both countries.
Nevertheless, courts have held that application for and receipt of landed immigrant status in another nation, without more, does not establish intent to abandon permanent residency in the U.S. It is a significant factor showing that one intends to give up U.S. residency, but is not conclusive.
Here are some solutions:
Get citizenship in one country or another. With U.S. citizenship, you can reside wherever you\'d like.
Apply for a Returning Resident permit. (For information on this permit, and other issues concerning Returning Residents, you may request an E-Mail report.) This permit diminishes---but does not eliminate---the chance that INS would be able to lift your green card.
Get a temporary work permit for one of the countries and keep the permanent residence in the other.
If you need information about the impact of holding green cards under Canadian law, please contact a Canadian immigration lawyer.