To elucidate its meaning and significance, a reconstruction of the textual ecology of Li Daoyuan’s Commentary on the Waterways Classic (Shuijing Zhu) from two angles will be conducive: the first is highlighting the commentarial nature of Li’s work, which draws attention to the constraints faced by the commentator as well as to the creative potential of a commentary relating to the primary text; the second is putting Li’s work in conversation with contemporary southern poetic writings on landscape to illuminate its special mode of space perception and representation. Li constructs an infrastructure of rivers based on an imperial vision. Although the empire was largely imaginary at this historical juncture, the riverine system is a powerful emblem of the medieval Sui and Tang polities, whose great canals supplemented the rivers.