回複：可以解釋得清楚些嗎?

Once you become a permanent resident of Canada by landing there, your permanent residency status is active. maple card is just a proof of that.
You can get maple card through these two ways:
Usually INS will initiate the maple card application for you. You don't need to do anything but to provide a Canadian address.
In rare case, if they don't do that, you can apply it by calling the Canadian INS when you are still in Canada: http://www.cic.gc.ca/english/contacts/call.html#prcard
I said that when you are in Canada because I am not sure whether you could reach this number when you are in US. I called that number when I was in Canada and it worked. The representative didn't ask me anything about not really coming to Canada. She just inititated the maple card application for me. I heard someone complain about not being able to reach Canadian INS after they come back to US. So it is safer to call INS when you are still there.