Abstract: The components of flora and plant species diversity of riparian plant communities of main channel in the Three Gorges area, and the hierarchical classification by the methods of TWINSPAN and DCA ordination were studied. The results showed that the components of flora were complex, the temperate type was dominant. The herbaceous habit of species was a little more than woody. The difference of plant species diversity between shrubland and grassland was not obvious. TWINSPAN divided the riparian plant communities into 6 groups for three levels . The distribution of groups seemly related with the moisture of habitats of plant communities. The habitat included floodplain, zone between upland and floodplain, beside water and stone gap near water. DCA indicated that riparian plant communities distributed along the gradient of moisture. 6 groups of riparian plant communities could be distinguished clearly in ax1 of DCA.