Common universalities exist in interpretation and translation of all languages. However, as interpretation and translation are communication processes that require language as a medium, it is undeniable that individual linguistic characteristics affect the end results of interpretation and translation to a considerable degree and that language is a crucial factor in interpretation and translation. Therefore, the characteristics of individual language are manifested, in one way or the other, in the end results. This thesis attempts to examine similarity between the Korean and Japanese languages from the aspects of syntax, phonetics, and vocabulary. Moreover, interference and the EVS (Ear Voice Span) are mentioned as the effects of similarity on Japanese-Korean interpretation and translation.