The purpose of this paper is to summarize research trends and analyze major discussions of previous studies on language policy and planning from a research historical perspective. In order to accomplish this purpose, this paper firstly established a database of related research lists through a complete enumeration survey of research articles by Korean researchers published in Korean academic journals. Then, based on the database, this paper summarized research trends of preceding studies by fields (status, corpus, education, etc.), by topics (language rank/function, orthographic norm, national language education, etc.), by relevant countries/regions (Korea, Asia, Europe, etc.). Finally, dividing the preceding studies into those related to Korea and those related to foreign countries, this paper analyzed major discussions by fields and topics based on representative and recent preceding studies. 'Not only does the aforementioned summary and analysis have research historical significance for preceding studies on language policy and planning, but 'they can also contribute to exploring the tasks and directions of future research.