According to Karl Popper's critical rationalism, criticism is the only way we have of systematically detecting and learning from our mistakes so as to get nearer to the truth. Meanwhile, it is arguable that the emphasis of Confucianism on creating a hierarchical and harmonious society can easily lead to submission rather than opposition, producing a conformist rather than critical mind. A question arises here as to whether Confucianism tends to denigrate criticism and thus run counter to critical rationalism. In this paper, I first argue that Confucianism prizes criticism and critical discussion, for which ample justification can be found in Confucian classics. Then I compare Confucianism with critical rationalism and assess the compatibility between them.