U.S high school Junior now canadian senior grading question

<p>Hi, My son finished his junior year in U.S and is now a senior in London Ontario. He had good grades throughout his studies and wish that his U.S grades are counted towards college admission in Canada next year. I am told that Canadian colleges only look at senior year grades. Is that correct? If not would they look at his U.S scores. Please advise if you know or how to get more information on this. Thanks</p>