The purpose of this paper is to give a pragmatic and sociocultural description of the discourse particle (DP) yey 'yes' in Korean. From a sociocultural perspective, a variety of discourse functions of yey are analyzed as a product of high-context communication strategies, which put interactional relationships before information delivery. For a pragmatic analysis, following Lee(1996, 1997, 1999, 2008), I assume that the DP yey has one basic sense of the speaker's positive attitude, and demonstrate that all the pragmatic uses of the DP can be inferred from the basic sense in accordance with the Gricean Cooperative Principle; all the pragmatic uses are broadly categorized into 2 groups, informative functions and politeness function.