This report deals with the issue of tense and aspect system in Korean both semantically and syntactically. Previous accounts for tense and aspect in Korean have been based on the assumption that the suffix has a fixed meaning, either temporally or aspectually, and either perfect(ive) or imperfective, and so on. In this report, I argue that the interpretation of the temporal suffix in Korean must be more flexible. The interpretation of the suffix is dependent on the occurrence conditions such as the characteristics of the verbs (or the predicates) and the temporal adverbials. For this claim, I argue how to understand tense and viewpoint aspect in Korean based on ‘twocomponent theory of aspect’ (Smith 1997) along the line of ‘boundedness’ of the grammaticalized aspect (Depraetere 1995) and ‘Event realization’ by Bohnemeyer and Swift (2004): –ess is either past tense or perfective aspect suffix and –nun is a present tense suffix with imperfective aspect meaning, because –nun only occurs with [+dynamic] predicates. Further, I argue how we can reflect the semantic tense and aspect onto the syntactic representation properly. Following Demirdache & Uribe-Etxebarria (1997, 2000), I show how tense and aspect in Korean can be mapped onto the syntactic representation. To treat the temporal adverbials, I follow Thompson (2005) that temporal adverbials are linked to [spec, AspP] position when they play a role as Reference Time (RT). Finally, I argue how the relations of the temporal arguments are syntactically realized in Korean. And –ess is interpreted as perfective aspect when the RT and ST (Speech Time) overlap. / text