Abstract: It has been ticklish to do rhetorical analysis quantitatively. Existing studies mainly focus on literary texts and rely on subjective reading in analysis. This paper intends to introduce a computer-aided empirical method for rhetorical analysis based on a case study of the State of the Union addresses from 1993 to 2008. DocuScope, a software dedicated to rhetorical analysis, and other tools for statistical data collection are used in this study. It is followed by close reading to further the analysis. It is found that the addresses by former Presidents Clinton and Bush demonstrate different rhetorical features and have different rhetorical effects. This case study shows that DocuScope, together with its embedded dictionary of rhetorical features, can help researchers to employ a consistent method and arrive at an objective and reliable rhetorical appraisal of texts. The study provides a new approach to the study of rhetoric and can be replicated for more systematic findings.