Expanded graphite (EG) and a mixture of EG and nickel (EG–Ni system) were ball-milled and subsequently annealed, respectively. The products were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscopy (TEM). After 100h milling, the average crystallite thickness (L c ) of EG and EG–Ni system deceases from 14.5 to 8.0 and 9.6nm, respectively, while the interlayer spacing (d 002 ) increases from 0.3341 to 0.3371 and 0.3348nm, respectively. It can be concluded that ball-milling decreases the crystallization degree of EG, while the additional nickel restrains this process. For the samples ball-milled for 80h, the disorder parameter I D /(I D +I G ) ratio of EG and EG–Ni system is in the range of 20.7–55.8% and 31.7–45.8%, respectively, implying that the presence of nickel is beneficial to more homogeneous ball-milling of EG. When the samples after ball-milling for 80h were annealed for 4h, the average crystallite thickness of EG and EG–Ni system increases from 8.5 to 9.0nm and from 11.8 to 15.5nm, respectively. It is deduced that annealing improves the crystallization degree of ball-milled EG, and the additional nickel is helpful for this process.