Hi
You may, no wait, you need to contact an attorney or at the very least look at your local entity that regulates businesses and ask them.
It's only legal if the goods you are selling are made in a sweat shop.
It's probably illegal. First, you're almost certainly on a student visa which either prevents you working or restricts you to a small number of hours. Secondly, you likely aren't even allowed to register a business in your host country.
Check it out here: http://www.cic.gc.ca/EnGLIsh/study/work-offcampus.asp
You will also have to obtain a business license.
Yes.Is it also need to get a business license if I sell clothing in ebay ?
Don't forget to register or license your business. Most localities require some sort of registration or licensure if you plan to own and operate a for-profit business of any kind. Laws vary by city, state, and nation, but you shouldnt assume that you can simply begin, without any sort of paperwork, buying and selling with the intent to generate income. Visit your local commerce authority and register your business so that you are engaging in commerce lawfully, rather than risking enforcement action.