This paper proposes a dynamic approach to anaphoric resolution in conjunction phrases, in terms of Discourse Representation Theory. Unlike Kamp, van Genabith, and Reyle (forthcomming)'s analysis, it proposes two different types of discourse representation structures for conjunction phrases; one for coordinate phrases such as and conjunction phrases and the other one for subordination conjunction phrases such as when subordination phrases. Following Chung (1992), Chung (2004), every element is processed in the order of occurrence and conjunction operators in a non-sentence-initial position cause the ongoing DR to split in two with the same index. DRS conditions and accessibility are accordingly modified so that DRs for conjunction clauses can be accessible from DRs for main clauses.