beta-MnO2 nanorods were successfully prepared by a simple refluxing route using manganese sulfate (MnSO4-H2O), sodium persulfate (Na2S2O8) and sodium hydroxide (NaOH) as the raw materials. The product was characterized by XRD, SEM, TEM, ED, EDX and TG-DTG. The results showed that the nanostructured materials were exactly manganese dioxides (pyrolusite) with rutile crystal structures and the diameter of beta-MnO2 nanorods ranged from 50 to 80 nm and the length ranged from 1.0 to 2.0 mu m. Meanwhile, the high yield (similar to 70%) of high-quality beta-MnO2 nanorods can be attained. The magnetic properties of the products have been evaluated using a vibrating magnetometer, which showed that the beta-MnO2 nanorods exhibited ferromagnetic characteristics at room temperature. (c) 2005 Elsevier B.V. All rights reserved.