Abstract: This paper analyzes the forming condition, main content and scientific value of Xi Jinping's important exposition on youth work. Formed upon summarizing the Party's fresh experience since the 18th CPC National Congress, Xi Jinping's important exposition on youth work is a scientific theory based on inheriting and developing the Marxist outlook on youth as well as the CPC's youth work theory. It systematically answers the overall, strategic and fundamental question of "what kind of youth we are to train, how to train and for whom to train". Meanwhile, it specifies comprehensively the position and function, responsibilities and missions, paths and methods, objectives and requirements of the youth work, which is the fundamental principle for the Party's youth work in the new era.