Fingarette thinks what is sacred in Confucianism is the element of human civilization modeled upon holy rite. Eno claims the holiness of Confucian ritual consist in its coherence with cosmic reality, Heaven. But both of them didn't think metaphysics is one intellectual focus for early Confucianism. Nevertheless, we think only in reference to a Confucian metaphysics which provides a sufficient exposition of the most generic features of cosmic reality, what is sacred in Confucianism can be fully clarified. Due to his unflinchingly sociological methodology, Berger's concept of religion as sacred canopy is partial and limited. His concept of "chaos" can't encompass all the cases in world religions, and his understanding of the holy as "the wholly other" deviates from its original expression in Rudolf Otto. Contributing to the innovation of Berger's idea of sacred canopy, Neville thinks religion is human engagement with ultimacy, and one of the most important functions of sacred canopy is cognitive, to know ultimate reality. Keeping to Neville's understanding of sacred canopy, we will analyze two key texts of classical Confucian metaphysics, Yijing and its "Great Treatise"(系辞), to try to illustrate what a Confucian sacred canopy is. Traditionally, shengsheng (生生) is understood as ceaseless creative advance into novelty, a most generic description of cosmic reality in Confucian metaphysics, but this understanding can't include the ultimate ontological creation of the world from nothing by ultimate polarity, which is also enunciated by Great Treatise. In relation to the Decision of Hexagram Qian, we can furthermore parse out four possible ways to understand shengsheng: to create creatures, to create this and to create that, this creates and that creates, and creatures create. They correspond to the four characters in the decision: initiation (元), permeation (亨), harmonization (利) and integration (贞), and indicate early Confucians' reflections about the ontological traits of ultimate reality: Heaven is the initiative, permeative, harmonious and integral creation. Heaven creates being from non-being, initiates the world as a ceaseless creative process; it creates everything, imparts creativity and form into every creature; and then every formed creature itself strives for being and creation in a dynamical relationship with each other. Based upon such a "cosmontology", a Confucian sacred canopy will be finally outlined and the importance of ritual in reference to that canopy will also be illuminated.