This study aims to analyze and explain the aspects of the vowels appearing in the interlanguages of Korean language learners based on the licensing constraints and elemsents. As a result of looking at the pattern of vowel pronunciation, Japanese speakers have pronounced / ㅓ / / / ㅗ / in the short vowel by adjusting it to the licensing constraints of Japanes. Chinese speakers pronounced monothong / ㅐ / and diphthong / ㅕ /. by eliminating elements. In the case of the short vowel /ㅏ/, / ㅗ / and the diphthong / ㅝ /, it is shown that they are pronounced separately according to the Chinese syllable structure and the licensing constrain of Beijing Mandarin. In the case of the diphthong / ㅝ /, Japanese speakers were pronounced with a monothong [ㅗ] while Chinese speakers were pronounced with [ㅜ, ㅗ]. (Hankuk University of foreign studies)
