There have been countless studies on the rhetorical question(RQ);however,few are on its argumentative function,and fewer still on its logical functions with regard to“enthymeme/rhetorical syllogism”,the core of Aristotle’s logos(logical appeal).This study,based on the incompleteness and probability features of“enthymeme”,attempts to systematically explore the distinct ways and generating mechanism of the RQ’s argumentative function,via examining the RQ-rich masterpiece,Liu Xie’s Wen Xin Diao Long(WXDL).After enthymematically analyzing RQs in WXDL,we find that the RQ enthymeme achieves strong deductive capability by implying or suggesting an assumption(as the major premise),providing a solid argument(as the minor premise),and suggesting or implying a claim(as the conclusion).Moreover,this inquiry shows that RQ’s logical functions are accompanied by salience of the suggested assumption or assertion inherited from the question itself.This investigation can not only provide reference for broadening RQ research scope and its research method,but also verify and even enrich Aristotle’s notion of enthymeme,thus promoting the exploration and application of core Western rhetorical concepts.