Na2Ti3O7 nanoribbons is synthesized via a convenient hydrothermal process. The characterization successively reveals that the nanoribbons have a good crystallinity and uniformity with the width of 6-120 nm, the length more than 10 mu m and the growth direction of [001]. The charge densities that deeply influence the flocculation are measured under the different pH conditions. The Na2Ti3O7 nanoribbons presents the novel retention and flocculation properties in the dual retention system combined with the cationic polyacrylamide. The nanoribbons with super-high-aspect ratio possess the very large bridging effect in the micro-particle retention aided system. (c) 2012 Elsevier Ltd. All rights reserved.