This paper compares three factors affecting prosodic phrasing in Korean: syntax, focus and speech rate. The Syntax and Focus constraints have been claimed to be stronger than the Speech Rate constraint, but it is not known which of these - the syntactic constraint (SYNTAX) or the focus constraint (FOCUS) - is stronger. Based on production and perception data, it is found that SYNTAX is stronger than FOCUS, both at normal and fast speech rates, though less so at fast rate.