One-dimensional α-MnO 2 and β-MnO 2 single-crystalline nanostructures were prepared by hydrothermal process. The products were characterized in detail by multiform techniques: X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Experimental results indicate that the temperature plays important roles in determining produce α-MnO 2 and β-MnO 2 nanorods. In addition, the as-prepared α-MnO 2 and β-MnO 2 nanorods showed excellent catalytic performance in the Fenton-like reaction.