Abstract: This study characterized the community structure and population dynamics of Paradombeya sinensis Dunn based on a newly discovered population in the Jiyi Grand Canyon. Quadrat-based surveys were conducted to analyze species composition, floristic elements, and population traits. Results indicated that: (1) P. sinensis occurred sporadically and discontinuously across dry-hot valley systems along the Jinsha River and its tributaries. (2) The families and genera within the P. sinensis community were predominantly of tropical biogeographic origin, while species distribution patterns corresponded more closely to temperate zones. (3) Although P. sinensis displayed high flowering and fruiting rates, seedling recruitment was severely limited, likely constrained by its unique evolutionary history, specialized habitat requirements, and intrinsic biological characteristics. (4) The population exhibited a “growth-decline” age structure, with seedlings (Class Ⅰ) representing the smallest cohort, indicating critically poor population regeneration. The Jiyi Grand Canyon population represents the largest, highest-elevation, most densely clustered, and least disturbed P. sinensis community currently known. Its demographic profile, indicative of a developing population nearing structural stability, suggests that this habitat offers optimal ecological conditions for species persistence.