One of the difficulties in spontaneous speech processing lies in the pausal phenomena. This paper describes an effect of incorporating pausal information into the syntactic rules, and an advantage of using an "utterance unit" as a processing unit in spoken dialogue recognition. A speech recognizer was implemented with utterance unit grammar and pausal information as word bigram probability. Recognition experiments were conducted using various goaloriented spoken dialogues. The method employing utterance unit grammar and pausal information showed best performance: content word detection rate is 50.4% for spontaneous speech, which was 8.8% better than the method based on sentence recognition without the constraints by pause information.