This paper explores prosodic marking of narrow (corrective) focus in Seoul Korean. Korean lacks lexical stress and it has a phonologized association between the Accentual Phrase (AP) initial segment and intonation. In the experiment, four speakers read sentences including a two-item list which were designed to elicit either an L or H AP-initial tone. The durational variations, the pitch events at prosodic boundaries, and F$\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}$span in 32 sentences read neutrally and 64 sentences read with one of the items under focus were analysed. The results show that the focused constituent consistently initiates a new prosodic phrase. I n comparison to the neutrally spoken or defocused counterpart, the focused constituent was more likely to be realised as an Intonational Phrase (IP) in some contexts . Bitonal IP boundary tones were more likely to occur under focus than monotonal tones. In addition, in focused constituents, durational expansion particularly at the phrase-edges, expansion in F$\mathrm{<mrow\; data-mjx-texclass="ORD">0</mrow>}$span, and raising of the phrase-initial pitch were observed. On the other hand, defocused constituents were not phonetically reduced compared to the neutral counterparts. The results imply that the phonetic cues spreading over the focused constituent complement the exaggerated prosodic boundaries.