While phonetic neutralization in different morphophonological environments is discussed in previous studies (Kisseberth, 1969), Korean palatalization is known as an uncommon phonological phenomenon because the morpheme boundary plays a role. This study investigates whether morpheme boundaries also affect allophonic /n/ palatalization in Korean and demonstrates that morpheme boundaries contribute to allophonic variation. By using ultrasound imaging of four native Korean speakers, this study examines differences in /n/ palatalization between two morphologically different sets of words in Korean - tautomorphemic words (e.g., /koni/ ‘swan’) and heteromorphemic words (e.g., /mun#i/ ‘door + NOM (nominative marker)’). Comparisons of the degree of palatalization before /i/ show significant differences among different morphological environments. The results from this study support Cho (1998; 2001)’s claim on boundary effect in Korean /n/ palatalization and suggest that there are individual differences in distinguishing various morphological conditions. (Yonsei University · Korea University of Technology and Education)