At the heart of the Huayan tradition stands the Avataṃsaka Sūtra (Flower Ornament or Flower Garland Sūtra, Chinese: Huayan Jing). This scripture is regarded as the foundational text from which the school draws its vision of the cosmos as a realm of radical interdependence and mutual interpenetration. Its great arcs of imagery and doctrine, including the famous depictions of the bodhisattva path, provide the scriptural ground for Huayan contemplations on the Dharma realm. Within this vast sūtra, particular chapters such as the “Ten Stages” and the “Entry into the Realm of Reality” became especially influential, as they richly portray the unfolding of the bodhisattva’s realization and the intricate web of conditions that bind all phenomena together. The school’s very name signals its deep identification with this text, which functions as both source and touchstone for Huayan thought.

Around this central scripture grew a body of treatises and commentaries by the Huayan patriarchs, which articulate and systematize its insights. Fazang, often seen as the great systematizer, composed works such as the Treatise on the Five Teachings and other commentarial writings that clarify the structure of the Buddha’s teachings and the distinctive perspective of the Huayan One Vehicle. These texts explore how the Avataṃsaka’s vision of the Dharma realm can be understood doctrinally and practiced contemplatively, so that the interpenetration of all phenomena is not merely a poetic image but a lived realization. Later masters such as Chengguan and Zongmi further developed this heritage through extensive commentaries on the Avataṃsaka Sūtra and related works, elaborating subtle frameworks for understanding how scriptural teaching, meditative insight, and everyday conduct interrelate. In this way, the Huayan canon is not limited to a single sūtra, but consists of a dynamic interplay between the Avataṃsaka itself and the interpretive tradition that grew up around it.