A person seeking a tourist visa needs to satisfy all the requirements of Immigration Canada and could have to produce the following:
1) A valid travel document, such as a passport;
2) Temporary visa;
3) Proof of good health (sometimes by way of a medical exam);
4) Ties in the home country that will bring them back to their homeland, such as a job, home, financial assets or family;
5) Proof that they will leave Canada at the end of their visit;
6) A letter of invitation from someone who lives in Canada; and
7) Sufficient funds to support their stay in Canada (i.e., accommodation, food and travelling).
http://www.cic.gc.ca/english/index.asp