Foreign Affairs Minister John Baird said the failure by the council to effectively respond to the crisis in the Middle-Eastern country was "yet another free pass for the illegitimate Assad regime and those backing it."
In an unusual weekend session, 13 members of the security council, including the United States, Britain and France, voted in favour of a resolution which backs an Arab League plan calling for President Bashar Assad to step down.
But Russia and China used their veto power to block the resolution.
Damascus has been a key Russian ally since Soviet times and Moscow has opposed any U.N. call that could be interpreted as advocating military intervention or regime change.
Baird says the "paralysis of power" at the U.N. is especially deplorable as it comes amid increasing violence in Syria, which Canada condemns.
"Those attempting to cling to power in Syria are morally bankrupt, and their disregard for human life is surpassed only by their cynicism over doing what is just and right," he said in a statement Saturday.
"Canada continues to support the efforts of Syria’s neighbours and others to resolve the current crisis. History will judge those whose obstruction serves only to prolong this senseless violence."
Baird added that Canada would stand with the people of Syria in their efforts to achieve a brighter future.
Activists in Syria say government forces have recently killed more than 200 people in the city of Homs as part of the violent crackdown against those protesting Assad's rule.
Assad's regime has denied the assault, calling the reports part of a "hysterical campaign" of incitement by armed groups against the government, aimed at a pressuring the United Nations to act.
The U.N. said in December that more than 5,400 people have been killed in Syria since March, but it has been unable to update its count for weeks due to recent chaos in the country.
The American Ambassador to the U.N, Susan Rice, used unusually strong language after the security council vote, saying the United States was "disgusted" by the vetoes and accusing Russia and China of aiming to "sell out the Syrian people and shield a craven tyrant."
Russian Ambassador Vitaly Churkin said he was encouraged by international statements about "the intention to continue diplomatic efforts" and noted that the security council is "not the only diplomatic tool on the planet."
Human rights advocates fear the security council resolution's failure might encourage the Assad government to intensify its violent crackdown on anti-government protesters.
Meanwhile, amid news of the violence in Homs, the Syrian embassy in Ottawa was vandalized.
RCMP Const. Julie Morel said the Mounties are investigating after the embassy's front door, sign and canopy were splattered with bright red paint.
An anti-Syrian government protest took place in front of the embassy earlier Saturday, but police say it was peaceful and there was no apparent link between the event and the vandalism.