depends on your connection with Canada. For example, your family, bank account, house, etc. You can fill out this form:
http://www.cra-arc.gc.ca/E/pub/gm/4-5-1/README.html
If you are not Canadian residence, you will not pay Canadian tax.
http://www.cra-arc.gc.ca/E/pub/gm/4-5-1/README.html
If you are not Canadian residence, you will not pay Canadian tax.