[Objective] The study aims to find out factors that influence the plant community structure and distribution pattern in the riparian zone along Ziya river, and provide references for related research. [Methods] In June, 2013, we investigated plant community structure and six environmental factors in 94 plots including altitude, levee type and land use type outside the levee in the Ziya river system. [Results] Totally, we found 249 species, which covers 51 families and 166 genera, of which, 199 species covering 43 families and 135 genera were found in the mountain regions in the mountainous region and 36 species covering 22 families and 35 genera were found in the plain. Phragmites australis, Artemisia mongolica, Vitex negundo, Artemisia annua were the dominant species in the mountain rivers and P. australis, Amaranthus retroflexus in the plain rivers. The species richness in mountain was significantly higher than that in the plain areas. [Conclusion] The altitude and the land use type outside levee significantly associated with the plant community structure. Hydrothermal conditions and human activities are the main factors affecting the vegetation composition and spatial distribution.