Abstract: Ternary graphite intercalation compounds (GICs), nitrate/nitric acid-sulfuric acid-GICs, were prepared by a two-step method. Their structure was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. Results showed that the two-step method favored the formation of lower stage-GICs by promoting the intercalation of nitrate or nitric acid and enlarging the interlayer spacing. The expanded GICs, whose expansion volume can reach 450mL/g, showed obvious graphite layers and a uniform porous structure. The two-step method had many advantages compared with the direct intercalation method, such as safety in operation, less pollution during experiments and ease of industrial scale-up.