Carbon nanofibers (CNFs) decorated by manganese dioxide nanoparticles (MnO(2)NPs) are prepared by an electrospinning technique, followed by thermal treatments in different environments. The obtained MnO(2)NPs-CNFs composite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM images showed that the surface of the CNFs was decorated with homogeneously dispersed nanoparticles with narrow size distribution. XRD and XPS characterizations confirmed the main composition of the nanoparticles was MnO2. Furthermore, for the strong catalytic oxidation ability of MnO2 toward hydrogen peroxide, the composite material was used as the matrix for nonenzymatic sensor construction. Cyclic voltammetry and amperometric response were applied to investigate the performance of the sensor. Under the optimum conditions, a wide linear range from 10 mu M to 15 mM (R = 0.9994, R represents the correlation coefficient) with a low detection limit of 1.1 mu M was obtained. The proposed sensor also displayed short response time, high sensitivity, good reproducibility and stability. These superior performances could be attributed to the large surface area and excellent electrocatalytic activity of the MnO(2)NPs-CNFs.