Kang Hilisuk. 1996. The Vowel Harmony of Changhtling Dialect. Linguistics 4, 1-24. The purpose of this thesis is to demonstrate the vowel harmony occurring between verb stem and the ‘-a/a’ X ending and this basis is used to explain the developmental process of vowel harmony and the direction of the change in Changhtling Dialect. The cases that the vowel of stem-final syllable has the light harmonic feature and the ending becomes `‘-a X’ are: First, when the vowel final syllable of the stem is /o/. Second, when the vowel of the stem-final syllable is an open-syllable stem with /a/. Third, in specific cases when the vowel of the stem-final syllable /σ/. Finally, the stem of p(ㅂ) -irregular verbs. That the phonetic ending ‘- X’ follows the vowel of the stem-final syllable corresponds to almost all vowels except for the case that is followed by ‘-a X’ ending. That is to say, when the vowel of the final syllable is a closed syllable with /a/ and the vowel is the stem with / , u, E, o‥,u‥, i, i/, V, the ending is changed to ‘- X’. This aspect coincides with the fact that the vowel hammy of Korean language is developing toward the dark vowel. This is shown by the examples when the vowel of the final syllable is changed to the stem of closed syllables and when the conventional neutral vowel /i/ is clanged to the dark vowelizing. (Chosun University)