This article presents a preliminary comparative study of the cosmopoetics of Lucretius and Liu Xie 劉勰, examining how each articulates a relationship between cosmology and poetic form. Through a comparative reading of De rerum natura and Wenxin diaolong 文心雕龍, it explores the ways in which poetic form is situated within broader frameworks of natural philosophy—Epicurean atomism on the one hand, and cosmological patterning grounded in the Yijing 易經 on the other. Rather than tracing direct influence or thematic correspondence, the study adopts a micro-comparative approach that focuses on analogical structures, figurative practices, and large-scale textual organization. It suggests that in both works, linguistic and poetic form is closely aligned with accounts of cosmic process, complicating conventional distinctions between mimesis and participation. On this basis, the article considers how each author positions the poet, or sage–philosopher-poet, as a mediator between nature and knowledge. The study contributes to ongoing work in Sino-Roman comparative poetics and proposes cosmopoetic form as a useful lens for comparative literary analysis beyond essentialist East–West models.