在正常的情形下，人類預期新地區的生活條件會更好，才會決定從原居住地遷移到另一個地區生活，就理論的觀點分析，人類遷徙的因素大致可區分為個人因素與結構因素，而此二者所導致的遷徙，勢將改變社會的發展，特別是移民所遷入的社會。 1949年，中國大陸超過百萬的人口遷徙到臺灣，顯然的，這是結構因素所致，這是一群人受到政治因素的推力而形成的大遷徙；由於當時移民占臺灣總人口數相當的比例，於是形成所謂的「外省人」族群，此族群對臺灣戰後的發展產生相當程度的影響。 本文試圖從遷徙作為的研究途徑，依循歷史演進的脈絡，以質性研究的方法，探討自1949-1996年移民與臺灣戰後的發展情形，並檢視近半個世紀以來，移民在臺灣政治、經濟與社會發展過程中所扮演的角色。 / Generally speaking, people believe that the living conditions of the new area will be better, then they make decision to migrate to another place to live. In the theory of migration, it can be divided into individual factors and structural factors. No matter which factor, migration will have an effect on the development of immigrant society. In 1949, there were over 1.2 millions of the people who migrated from mainland China to Taiwan. Undoubtedly, it was caused by the structural and political factors that pushed the “great migration”. Because the immigrants moving into Taiwan accounted for a considerable proportion of the population, they formatted an ethnic group so-called "mainlanders". This paper attempts to use migration as an approach to review and explore the development of society in Taiwan in the second half of the 20th century. The time frame is between the year of 1949 when the Nationalist government immigrated to Taiwan and the year of 1996 when direct presidential election took place in Taiwan.