本文旨在針對學期制度的變革可能性進行探討。我國的學期制度依法係屬於中央政府的教育權限，因此，國民中小學也自1945年起，在相關法規的規範之下實施二學期制度迄今。然而，為順利推動十二年國民基本教育，教育部有意自104學年度起，以試辦方式增加第三學期，此構想甫一提出，隨即引發各界對學期制度及其實施可能性的探討。為了解學期制度之相關概念，本文首先就學期之定義進行闡述，在說明我國學期制度的規範以及主要國家學期制度的概況後，再以日本國民中小學自2002年開始，將原有的三學期制調整為二學期制的經驗為例，從制度上的觀點分析我國學期制度的變革可能性，期能做為教育政策轉化為制度時之參酌。

The purpose of this article aims to address the possibilities of changing semester institution. Because the authority of setting semester for schools in Taiwan belongs to the central government based on relevant laws, elementary and secondary schools, therefore, began implementing their semester system since the year of 1945. However, to implement the 12-year basic education successfully, the Ministry of Education intends to introduce the 3rd semester as a pilot program for elementary and secondary schools from 2015, discussions of the definition of semester institution and its feasibility were initiated immediately after proposition of this idea. In order to understand the concepts of semester institution, the first section of the article is to review the definition of semester, then illustrates the rules of semester institution in Taiwan as well as taken in major countries. In the third section, this article analyzes the possibility of changing semester for our nation with an institutional viewpoint based on the case of semesters adjusting experiences from trimester to semester in Japan’s elementary and secondary schools. Finally, this article ends with some concrete suggestions might have for authorities while turning educational policies into institutions.