Ni nanoparticles filled carbon nanotubes were prepared by anodic arc discharging plasma. The composition, the morphology and the phase structure of the products by this process were investigated via the high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy and X-ray energy dispersive spectrometry (XEDS). The present experiment technology can obtain great amount of the carbon nanotubes filled with metallic nanoparticles, it means that inside there are Ni nanoparticles with fcc structure, outside thin layers are well-graphitized nanotubes. The diameter of carbon nanotubes ranges from 30 to 40 nm, the wall thickness is approximately 5~8 nm, and the particles encapsulated in carbon nanotubes are scattered homogeneously in spherical or ellipsoidal shapes.