Moon, Hyun-Hee. 2017. “Changes of English Company Names in KOSPI: From the 1940s to the Mid-2010s”. The Sociolinguistic Journal of Korea 25(1). 53~83. This study aimed at investigating to what extent, in what ways, and for what purposes English has been used in Korean company names from the 1940s to the mid-2010s. Of those registered in KOSPI (the Korea Composite Stock Price Index) in July 2014, 165 companies with English names were chosen for the study. In order to grasp longitudinal trends, the linguistic composition of original names and subsequent name-changes were analyzed. The results demonstrate that Korean was the dominant language of company names between the 1940s and the 1970s, while English gained popularity in the 1980s and since then, consolidated its position as the most attractive lexical source. A Single word was the first form applied to English names, followed by a compound and an acronym. Since the 1990s, more complex forms combining clipping and blending have been widely employed, diversifying word formation types. Parts of speech, once limited to nouns, adjectives, and verbs, have later broadened to include articles, prepositions, and conjunctions. The major reason for the influx of English names is the positive images of English which connect them with being modern, global, progressive, future-oriented, and high-tech. The study shows that Korean companies have also discovered a new linguistic advantage of English, which has permitted them to incorporate diverse meanings into their names, and this has played an important role in strengthening the position of English.