The goal of the present study is to identify the topic trend in the field of library and information science in Korea. To this end, we collected titles and abstracts of the papers published in four major journals such as Journal of the Korean Society for information Management, Journal of the Korean Society for Library and Information Science, Journal of Korean Library and Information Science Society, and Journal of the Korean BIBLIA Society for library and Information Science during 1970 and 2012. After that, we applied the well-received topic modeling technique, Latent Dirichlet Allocation(LDA), to the collected data sets. The research findings of the study are as follows: 1) Comparison of the extracted topics by LDA with the subject headings of library and information science shows that there are several distinct sub-research domains strongly tied with the field. Those include library and society in the domain of “introduction to library and information science,” professionalism, library and information policy in the domain of “library system,” library evaluation in the domain of “library management,” collection development and management, information service in the domain of “library service,” services by library type, user training/information literacy, service evaluation, classification/cataloging/meta-data in the domain of “document organization,” bibliometrics/digital libraries/user study/internet/expert system/information retrieval/information system in the domain of “information science,” antique documents in the domain of “bibliography,” books/publications in the domain of “publication,” and archival study. The results indicate that among these sub-domains, information science and library services are two most focused domains. Second, we observe that there is the growing trend in the research topics such as service and evaluation by library type, internet, and meta-data, but the research topics such as book, classification, and cataloging reveal the declining trend. Third, analysis by journal show that in Journal of the Korean Society for information Management, information science related topics appear more frequently than library science related topics whereas library science related topics are more popular in the other three journals studied in this paper.