目前台灣的少子化、人口結構老化，已嚴重影響到中小學教師的需求量，各縣市政府為因應此趨勢，要求學校有正式教師缺額不要聘滿，保留缺額給代理、代課或兼任教師，如此反而使得每年新聘代理代課教師員額多過正式教師很多，而在成為正式教師前，要想進入中小學工作職場，先行代理代課，有可能成為常態，對台灣的師資培育產生不小的影響。本研究乃採個案研究法，針對一位私立大學畢業，已取得合格教師證書的國中初任代理教師，藉由文件分析、訪談、觀察及反思札記，了解個案在代理一年的心路歷程，面對當下的教育工作與接下來的教師甄選，雙重壓力的因應，以及個案代理過程的同事關係、師生關係、親師關係，並整理其代理經驗，提出對師資培育、教師甄選制度的建議。

In Taiwan, the change of population structure has reduced the amount of formal teachers in middle and primary schools already. For this trend, every county and municipal government requires to keep vacancies for substitute teachers or part-time teachers, in order to keep the formal teachers' jobs while making a reduction of the classes the coming year. This trend also influences Taiwanese Teacher Education Program. The substitute teacher stage will become the alternative process of teacher education. Most of intern teachers must be substitute teachers in the front of being formal teachers. This research used case study. It collected research data by way of data, interviewing, observation, and, reflective notes. It sought one substitute teacher who had teachers' qualified certificates graduated from the Chinese department of private university as research subject. The purposes of this study were following. Firstly, the developmental process of substitute teacher during two semesters. Secondly, what were their solutions when substitute teacher faced with the approach- approach conflict between tutor’s job and teacher’s selection. Thirdly, the interpersonal relations of substitute teacher were among peers, pupil, and parents. Fourthly, the results of this study provided for the implication of teacher education program and teacher selection system.