The purpose of this study is to examine the function and spread of English in Korean academic society by investigating the use of English in writing dissertations. To this end, this study selected one of the universities in Korea and attempted to identify to what extent English has been used in master"s and doctoral dissertations for the last 12 years. The results show that the use of English in writing both master"s and doctoral dissertations has increased gradually and there exists a discrepancy among the fields of study. The results also reveal that a number of dissertations in the fields of natural science, engineering and medical science have been written in English recently. The comparison of the results of this study and some related analyses in European universities indicates a similar trend of English use in academic fields. Understanding the current use of English in Koreanacademic society can lead to a better understanding of the role and function of English in Korea as a whole.