First, you should take the Death Certificate to a Notary Office in Toronto to get a Chinese version, then apply for Notarization for English version and Chinese Version, second, go to the Ministry of Government and Consumer Services of Ontario to apply for Authentication, third, go to China Consulate in Toronto to apply for Authentication.

Ministry of Government and Consumer Services affairs
9th Floor, 77 Grenville Street, Broadway, Toronto ON M5S 1B3, Tel: 416-3258416 Fax:416-3258434

PSB: All documents emanating from Canada should be accompanied with Chinese translation. Both the original and the translation must be legalized by the Embassy or Consulate General of China in Canada before being used in China.