Justin Trudeau，the leader of Liberal Party，won the 42nd federal election of Canada in Oct，2015，putting an end to the 9-year Conservative government. The Conservatives，due to its Augean Stables，has lost the affection of the majority of Canadians both in the fields of internal and foreign affairs. Trudeau，with the slogan of “Real Change”，has opened a new page of Canada’s Party politics，and whether he can realize real change will be the key first step to verify his ability of governing，and will also be weather vane of the trend of Party politics. This paper will study the adjustment and future trend of Party politics in Canada by analyzing the features of the federal election in 2015 and the internal and foreign policies of the Liberal government.