Purpose: We collected the data of Science Citation Index (SCI) and SCI Expended (SCIE) papers written by the members of the Korean Society of Radiation Oncology (KOSRO) to analyze the current status and the future trend. Materials and Methods: We searched the database of SCIE for the period from 1981 to 2011 at the Web of Knowledge site. Articles, reviews or proceedings written by KOSRO members as the first or corresponding authors were included. Search terms were the following combination of subject headings: therapeut radiol, radiat oncol, Korea. For National Cancer Center, combined search terms such as natl canc ctr, Korea and the names of faculties were applied. Results: The total number of SCIE papers was 547. Numbers of the published papers in 1995, 2000, 2005, and 2010, were increased continuously, which was 2, 14, 40, and 83, respectively. The average impact factor was 2.9. The papers were published at the 134 different journals. The proportion of "International Journal of Radiation Oncology Biology Physics" was 23.4% of all the papers. The number and proportions of papers by subject categories were 87 (15.9%) in biology, 73 (13.3%) in physics and 387 (70.6%) in clinics. The papers of the top five institutions, based on the number of published papers, occupied 66.3%. Conclusion: The number of SCIE papers is increasing rapidly in the field of radiation oncology in Korea. To improve the quality of papers, multi-institutional retrospective or prospective randomized studies should be done for the common cancers in Korea.