The aim of this present study is to clarify the role of the intrinsic laryngeal muscles in production of Korean consonants, especially he physiologic activity pattern of the vocalis(VOC) and posterior cricoarytenoid(PCA) muscle. It is generally known that in Korean there is a three-way distinction in both manner and place of articulation classified as glottalized, lenis and aspirated consonants, and there are several reports for differentiating the three manner categories with acoustical and physiological research. But authors know that there is no report about the electromyographic study with the PCA muscle for the production of three types of Korean consonants in English literature. So authors tried to investigate the role of the intrinsic laryngeal muscles, and results indicated that aspirated consonants appeared to be characterized by marked and earliest activation and reactivation of the PCA and VOC muscles before voice onset of the following vowel, and lenis consonants by moderately activated and reactinated, but glottalized consonants by none or slightest activation of the PCA and marked reactivation of the VOC for the production of consonants. SO it seems resonable to consider that the PCA muscle takes part in important role for the production of consonant before voice onset of the following vowel, especially aspirated and lenis consonants.