In recent years, much research has been carried out on body-part terms in expressing metonymic and metaphorical notions in terms of embodiment in cognitive linguistics. Among the terms, heart-centered expressions have been widely explored in English and other languages to show the significance of our bodily experiences in expressing our emotions as well as interpersonal or social relationships. However, little research has been carried out on the metaphoric expressions of chest or breast (cf. Kövecses 2002, Lakoff & Johnson 1980). The purpose of this research is to explore literal and metaphoric meanings of kasum ‘chest/ breast' in a Korean written corpus in terms of corpus linguistics and conceptual metaphor (Perez 2008, Berendt, et al. n.d.). This research analyzes 2,373 tokens of kasum, 114 ces-kasum ‘milk-breast' and 355 simcang ‘heart' from the Sejong Project Corpus. Cognitive linguistic research has shown that the head is usually related to mind/reason but the heart to emotion/feelings in many languages. However, examination of the Korean data shows that simcang is used literally in most cases as a technical term in medical contexts, and that ces-kasum is used literally in most cases to refer to a woman's breast. Unlike these two body-part terms, kasum is used as a cover term to express not only the upper body part literally but also an entity as a locus and perceiver of emotion/ feelings metaphorically. Examination of the corpus data shows the following major findings: (i) 819 tokens (34.5%) are used to refer to the body part chest literally, 1,512 tokens (63.7%) metaphorically (Deignan 2005), (ii) 921 tokens (38.8%) are used to show physiological responses in expressing emotion/feelings, using such terms as “the chest is aching, pounding, choking/being blocked, trembling, sinking, etc.”, (iii) 412 tokens (17.4%) are used to show kasum is a locus for emotion. As these findings show, in Korean, as folk knowledge contrary to the scientific knowledge about the roles of the brain, kasum is viewed as a locus or perceiver for emotional feelings in response to physical/ physiological stimuli. The findings show that the folk knowledge forms the basis for conceptual metaphor for kasum: (i) a locus for feelings, (ii) a container of emotions, (iii) an entity/a material, (iv) a storage/hiding place, etc. Finally, this research shows that in Korean, unlike in English and some other languages, kasum plays an important role in expressing emotional feelings, displaying conceptual metaphorical meanings derived from folk knowledge.