Spoken dialog system for human computer interface and response method therein

A dialog type voice interface system and a responding method thereof are provided to create an output sentence according to intention of a user and situation of the system to realize a natural dialog between the user and the system. A voice recognition unit(100) recognizes voice of a user. A knowledge search unit(104) searches for information matching with the voice of the user from plural sentence information contents. A dialog model unit(102) transmits information corresponding to character sequence signal of the recognized voice to the knowledge search unit, and sets a dialog model by the searched information. A system response unit(108) creates a sentence frame candidate based on the set dialog model, and determines the ending type of the sentence according to user-spoken sentence and system situation to generate an output sentence. A voice synthesis unit(110) converts the output sentence into voice, and outputs the voice.