Can a Canadian get a 90 day multiple entry M business visa?

Dear, as far as I know, usually, you may be given a 60-day business M type. But it’s possible for you to get 90-day M type. You can have a try.
Please note that once you apply for a business M type, your current tourist L type will be cancelled.
Or you can go there with tourist L type and stay for 60 days. Before it expires, you can apply for an extension. In this case, you can stay for more than 60 days.

Patricia. Thanks for the info. But could you please clarify something about what you said. I understand that if an M type is granted of course the L type would be cancelled. But what if the M type is not granted, would the L type still be cancelled and would I have to re-apply for it? Or would my passport just be returned to me with the L type designation still valid? Thanks!

Dave, if the M type application is not passed, I think the L type is still valid. But you’d better contact with the embassy of PRC to confirm that.

Thanks Belle!
I found from internet:
All foreign nationals traveling to the People's Republic of China must travel on a valid passport with at least six(6) months remaining validity after the entry date into China.
I don't know if the requirement above is an old version years ago. What is your suggestion on this?

As far as I know, when you apply for it, your passport should have a remaining validity of at least 6 months.