A series of Expanded Graphite (EG) with different Expanding Volume (EV) were prepared by the two-step chemical intercalation, and the microstructures and morphologies of the EG particles and their precursors were obtained by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and a stereoscopic microscope, respectively. The extinction behaviour of EG for 1.064 μm laser was measured by a static test, and then the average mass extinction coefficient was calculated and its dependence on EV was obtained and subsequently analyzed by the extinction theory. The results show that EG particles with different EV, especially with an EV of 600 mL·g-1, may be prepared by controlling the synthesis conditions of the precursors, namely graphite intercalation compounds. The average interlayer spacing (d002) of the precursor for EG becomes larger than that of Natural Graphite (NG) due to the two-step intercalation, and the EV of the EG whose precursor’s d002 rises from 0.3590nm up to 0.3711nm, increases from 267 mL·g-1 to 600 mL·g-1. The average mass extinction coefficient of EG depends near-linearly on its EV, and rises from 0.20 m2·g-1 up to 0.48 m2·g-1 while the EV increases from 233 mL·g-1 up to 600 mL·g-1 in the static test. The phenomenon of nonselective scattering occurs when an incident 1.064 μm laser reaches to EG particles, and then the larger is the surface area of an EG particle owing to a higher EV, the stronger is its scattering power to 1.064 μm laser. Meanwhile, much deeper pores and cavities appear with the EV increasing, and may work as equivalent black bodies to improve EG absorption of the incident laser.