In this study, realization of strong and weak syllables in English by Korean leaners with low English proficiency was examined through experiment. The aspects of three acoustic characteristics-duration, pitch, amplitude-were measured and compared with native speakers of English. It was assumed that production of duration, pitch and amplitude of strong and weak syllable by Korean learners would be different from that of English native speakers. According to the production experiments, English native speakers produced strong syllable longer, higher and louder than weak syllable. However, Korean leaners produced strong syllable higher and louder than weak syllable, but not longer enough. Specifically, weak syllable by Korean leaners was longer and strong syllable shorter than native speakers. Furthermore, the difference in duration of syllables between Korean leaners and English native speakers is more significant than pitch and amplitude. As a result, the duration was more important cue for the realization of stress than pitch and amplitude. However, Korean leaners did not produce duration of stressed syllables as English native speakers did, even though they produce the pitch and amplitude of stressed syllable in a similar way to native speakers. The reasons for those were considered, too.