Grinding effect on graphitization of non-graphitizing carbons such as phenol-formaldehyde resin carbon carbonized to 700°C (PF-7) and 900 °C (PF-9), and charcoal was investigated. The sample of one gram was pulverized by agate mortar for times ranging from 1 to 100 hrs and then heat-treated at various temperatures. The graphitization behaviour was examined by the observation of diffraction profiles of (002), (110) and (112) lines in the heat- treated samples.The effect of grinding on graphitization was found after heat-treatment of the ground sample at high HTT, such as 2600 and 3000°C. The ground sample showed a composite (002) profile, though the original showed only a broad, almost symmetrical profile. The composite profile consisted of two sharp peaks, at about 26° and 26.5° in scattering angle in addition to a broad band. From the change of the profile with grinding time, it was found that graphitic component increased to a maximum and then decreased with increase of grinding time.