In this paper, I examine word-initial tensification in modern Seoul Korean, and suggest that this tendency must be handled with language-internal effects. Several decades of research have assumed that word-initial tensification can be regarded as a wrong habit of language which reflects speech errors or frivolity of the public. But all words don’t show this tendency, and so there must be some principles or tendencies pursuing further. The following is the findings of this study. 1) Comparisons with other dialects in Korean show that other dialects have affected this tendency. 2) The tensificaion should be considered to be realized in the morphemic level. becaise it appears in specific morphemes, 3) Concerned with its semantic or functional contributions, the tensificaion gives a discrete meaning difference, and otherwise it can be considered to have ‘strengthening’ effect. Finally, ‘Avoid homonym’ principle motivtes the word-initial tensification.