Based on conceptual metaphor theory and speech act, this study aims to examine the communicative functions of language use by analyzing texts used in Seoul’s urban design. Considering that life in a modern society is based on the ecosystem of its cities, the importance of urban design in increasingly felt by modern individuals who share limited space and move along predetermined routes. According to El-Khoury and Robbins (2004), urban design is both an abstract and relative concept, and the purpose of a city can be interpreted differently according to differences in experience and perspective. Conceptual metaphorical language expressions not only have a communicative function but also provide the hearer with a certain perspective by concretizing the events or phenomena indicated by the speaker. Metaphorical language expressions based on metaphors created by the speaker perform speech acts by serving as an effective means of persuasion and communication (Searle 1979). We examine the linguistic aspects based on the metaphor of the development of illocutionary forces in Seoul’s urban design texts.