This study investigates whether/how English-learning Korean speakers utilize allophonic cues such as aspiration and glottal stops in order to identify word boundaries in English. Given that speech stream is inherently continuous and causes segmentation problems, it has currently been a controversial issue whether and what types of segmentation strategies L1 and L2 speakers adopt in word recognition and perception. Previous perception studies (Altenberg 2005; Ito and Strange 2007) showed that Spanish and Japanese learners of English are not as highly sensitive to allophonic cues like aspiration and glottal stops as native speakers of English. The purpose of this current study is to directly compare previous two studies with the result with English-learning Korean listeners. Thirty intermediate or advanced learners participated in perception experiments to see whether/how they segment word boundaries in English. The result showed that they utilized both aspiration and glottal stops above chance level, but that unlike our expectation, glottal stop stimuli were easier to perceive than aspiration stimuli. Furthermore, such results sharply pattern with those with Japanese and Spanish L2 learners even though both allophonic cues differ in utility in their consonant systems and the status of glottal stop differs in all three languages. Based on the current study, two interesting implications are provided. First, L2 learners might acquire phonetic-fine details though their sensitivity is not as high as native speakers, supporting Kuhl and Iverson (1995). Second, more reference to glottal stops over aspiration indicates that the former might be less marked than the latter across languages at least in the field of L2 phonetic or phonological acquisition.