The purpose of this study is to find out how Korean students who are learning Japanese perceive long vowels and short vowels in Japanese. 61 students are divided into two groups for testing. The grouping is made according to the accent feature. The perception of each student is measured with a listening test of 68 words that have different pitches, long vowel positions, and accent types. From this test we are providing following results. First, Students have more troubles in perceiving long vowels than short vowels. Second, through this study, there is no doubt that Korean learners`s perception of long vowels is influenced by pitch types. Third, Kyeongsangdo-diaclect speakers are more persive than Seoul speakers in some pitch types. Forth, It is more difficult to perceive the long vowels when those are in final position compared to the in the initial or middle positions. Finally, Kyeongsangdo-diaclect speakers can perceive more accurately in the HLL accent type, HLLL accent type, LHHL accent type and LHLL accent type than Seoul-dialect speakers.