A Comparison between Dissimilation in Diachronic Approaches and OCP-Markedness Constraint Kwan-Young Oh (Chonnam National University) This paper is to consider dissimilation in a few words when two similar elements occur in adjacent position. Although there are varying views of what causes this dissimilation, the generally accepted point of view is that dissimilation occurs so as to provide for easy pronunciation. In this paper, I have considered the dissimilation in two aspects, one of which is based on diachronic approaches and the other within an OT framework. As for the diachronic methods, I have considered the analytic methods of SPE, Schane, Katamba, and Archiangeli & Pulleyblank, but these methods are not fully satisfactory in explaining this phenomenon. Within the OT framework, I have explained the dissimilation through a few constraints. Especially, in this point, OCP plays a key role in explaining the dissimilation. One interesting case is about circle>circular and particl