Mathematics is an important subject of foundation tool. There are many discussions about Taiwan mathematics teaching hours every week in “Curriculum Guidelines for 12-Year Compulsory Education.” In this thesis, the authors focus on the track of Taiwan mathematics teaching hours’ changes in different period, and compare them with other countries. The author then introduces the methods of students’ mathematical ability promotion in other countries, and argues the influence of teaching hours reduction. Lastly, the author analyzes the contradiction and conflict of idealism and realism, carrying his proposition, reflections and questions.