Prosodic characteristics of a simulated dialogue have been analyzed and compared with those of read speech. The simulated dialogue was produced by referring to a written text, while read speech was produced by reading individual sentences of the same text in isolation. Analysis of fundamental frequencies and speech rates indicated that dialogue-style utterances have larger mean value and standard deviation of fundamental frequencies as well as higher mean value of speech rates than reading-style utterances. Further analysis of the F0 contour parameters extracted by using a quantitative model has revealed that the differences in the F0 characteristics are caused by a higher baseline value of the F0 contours as well as an expanded range of variation in the amplitude of accent commands in the dialogue-style utterances.