This paper investigates factors that influence pause duration in Chinese reading texts through examining the stress degree in pre-pausal and post-pausal positions and the rhetorical structure in discourse as a whole. The RSTTool is used in diagramming the rhetorical structures of the texts. The recordings, extracted from the ASCCD corpus, are further analyzed acoustically and statistically by applying Praat and R. The statistical analysis results show that the stress degree in both pre- and post-pausal positions has a significant impact on pause duration. Moreover, the nuclearity in both positions have also been shown to have a remarkable influence. Specifically, the nucleus in pre-pausal and satellite in post-pausal positions can significantly lengthen the pause duration.