This article examined the relationship between the Grain Tribute System and spatial structure of canal-side space along a part of the Grand Canal called Caohe (the Canal for Grain Tribute) during the Ming and Qing dynasties. The Grain Tribute System refers to the comprehensive and systematic structure established by the government to support canal transportation, which includes not only the canal, but also water conservancy facilities, post stations, granaries, management buildings, officials and laborers dedicated to managing and overseeing the canal transportation. Then the article analyzed historical materials and ancient maps to examine spatial structure of the canal-side space of Caohe.