As a view of government phonology, this thesis analyzes interlanguage phenomenon that is frequently misused by Chinese and Japanese when they learn Korean. The interlanguage phonology is able to divide into segment, sound alteration, syllabic structure. The aspect of inter-language can be verified by observing errors which are appeared each part of phonology. Errors, that are occurred when foreigners speak the Korean consonant and when speaking the segment-sound (the double-vowel /ㅖ/ and the singular-vowel /ㅐ/), are explained by syllable-structure and element of governmental phonology. Japanese and Chinese have a fundamentally different syllable- structure because they don`t speak the domain-final empty nucleus. So they often make errors when they speak Korean by excepting Korean consonant or inserting the vowel /ㅡ/. These errors appear when speaking Korean by changing construction elements to follow Chinese phoneme- system because, in the segment, phoneme-system isn`t same between Korean and Chinese.