My boyfriend is a Canadian citizen but is a legal us resident. what do he need to travel to Canada and back?

I think he may just need photo id and possibly his birth cert. just in case:)

Until the end of the year, drivers license or birth certificate, but there are plans to require passports for travel to "local " countries starting in 2007.

Here's what I found at askjeeves.com

Canada has an open border with the United States, so crossing the border into Canada will be easy, but youll need to plan ahead. Passports are not required for native-born citizens of either country, but proof of citizenship will be required. If you have a passport, bring it or bring a certified copy of your birth certificate along with a photo ID issued by a government agency (such as a drivers license if it has your picture on it). Alien residents of the United States should have a passport and Alien Registration Card (green card; U.S. Form 1-551), but are not required to obtain a visitors visa before traveling to Canada. Citizens of countries other than the United States who are not alien residents of the United States must have a passport and may also need visitors visas. For further information, please contact the nearest Canadian Consulate or the Canadian Embassy at 1-202-682-1740, prior to departure . You can also find information about travel in Canada at http://gocanada.about.com/library/weekly/aa02198.htm.

You need a Canadian past port for easy in and out of Canada

He should bring his Canadian passport and his U.S. immigration papers (green card, I assume).

Going into Canada with a driver's licence is easy. Coming back to the U.S. with that only that type of documentation is not as easy.

It's best to have every shred of legal documentation with you. I'd even recommend bringing a U.S. business card and driver's licence to prove that he really does live in the U.S. in case he gets asked.

The only thing you maybe asked for is Photo ID and possibly a birth certificate. If he is a Canadian citizen he can come home anytime. If you are an immigrant of the US (not American) you will need your papers and if you are American you also only maybe asked for your Photo ID and Birth certificate. We still have an open boarder between our countries and hopefully that won't change anytime soon.

Just some legal ID. If he really wants to be fussy he can bring his passport.