A system and a method for synthesizing a dialog-style speech using speech-act information are provided. According to the system and the method, tagging for discriminating an intonation is performed for expressions whose intonations need to be differently realized depending on a dialog context in a dialog text using speech-act information extracted (from the) sentences uttered by two speakers having a dialog. When a speech is synthesized, a speech signal having an intonation appropriate for the tag is extracted from a speech DB and used, so that natural and various intonations appropriate for a dialog flow can be realized. Therefore, an aspect of an interaction in a dialog can be well expressed and thus improvement of naturalness in a dialog speech can be expected.
System and method for synthesizing dialog-style speech using speech-act information