The synthesis of new materials containing multi-walled carbon nanotubes (MWCNTs) and the microstructure of alumina particles were investigated and characterized. The MWCNTs and alumina particles were ground under both the dry and wet conditions with various rotation speeds (200–400 r/min) in planetary ball milling machine, and their combination characteristics were described. The experimental results were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and particle sizing analysis (PSA). SEM result revealed that the combination of MWCNTs — Alumina particles mixed quite well under both the dry and wet grinding with rotation speed of 400 r/min. XRD characterization indicated the better result could get in ground samples at a rotation speed of 400 r/min. PSA result showed the particle size decreased with increase the grinding speeds. From the overall results, we observed that the grinding method can be used to synthesize new material with high efficiency.