MOU Zongsan's use of "external transcendence" and "immanent transcendence" to differentiate Christianity and Confucianism has stirred long-lasting debates. Although most of the related discussions center on modern philosophy or Christian tradition as a whole, it is the aim of this article to reevaluate MOU's concept of transcendence through the perspective of Pseudo-Dionysius. This article first reviews MOU's idea of transcendence, revealing his hidden agenda and concern behind this concept; then it traces the notion of transcendence in the corpus of Pseudo-Dionysius, making a distinction between ontological-epistemological transcendence and religious transcendence in Dionysius's thought; finally it concludes that actually there are many similarities between MOU and Dionysius, while their differences actually manifest in two forms of the immanent transcendence-as person or as rationality.