The purpose of this study is to find out the perception of the vowel length in modern Korean and it’s phonetic realization of speakers from Seoul and Gyeonggi-do Area. The length of the vowel is known as one of the distinctive feature in Korean, however, it has been reported since 1960s that the distinctive feature of vowel length has entered the stage of loss. To find out the phonetic realization of vowel length, several sentences with words including long and short vowels were given randomly to read out loud. Then the subject was asked to mark on the words with long vowels to find out the perception of the vowel length. Results of the survey and the empirical data shows that the only limited number of subjects distinguished the length of vowel from the survey. Also, perception of the vowel length corresponded only 1% to it’s realization, which shows a great contrast from the experiment conducted in the end of 1980s where the perception of the vowel length corresponded to it’s realization by 75%. Thus, vowel length in Korean appears to be in the last stage of loss. (Ewha Woman’s University)