The purpose of this study was to examine the use of Korean transcriptions in Mongolian for names and place names in loanword usage and to propose a unified Korean transcription method for them. The Korean Loanword Orthography, which has written rules for each language, does not have rules for Mongolian, resulting in confusion about the naming of people and place names, as well as major historical and cultural examples between the two countries. To address this, we analyzed the Mongolian language that appeared in the usage of foreign words for names and place names and compared them with Korean writing standards. The analysis showed that there are examples of Korean transcription for 18 Mongolian consonants and 11 vowels. While there was a slight difference in Korean transcription when Mongolian consonants were used before or at the end of a consonant, there was no difference from the results of the previous study when Mongolian consonants were written before vowels. Mongolian vowels were also broadly consistent with the results of previous studies, but ‘о, ө, у’ differed in Korean transcription. In addition, we looked at usages based on the principle of idiomatic notation, such as “몽케칸(Мөнх хаан), 귀위크칸(Гүег хаан), 칭기즈칸(Чингис хаан), 울란바토르(Улаанбаатар).” Therefore, in the future, further discussion on the Korean transcription of Mongolian is needed, along with the collection of more usages and research on the scope of application of idiomatic orthography and the recognition of speech. Based on these discussions, we hope to establish a uniform bylaw for the Korean writing of Mongolian names and place names in loanword usage.