Abstract: The electromagnetic interference(EMI) shielding effectiveness(SE) of the graphene sheets/polyaniline (GSs/PANI) composite in different contents of GSs was investigated. The high crystalline GSs were prepared by DC arc-discharge method. The GSs/PANI composites were synthesized by an alcohol-assisted dispersion and pressing process. Compared with the pure PANI materials’ Raman spectra, the GSs/PANI composites show the decrease of the characteristic peak intensity or a red shift of the peak, which is induced by the interaction between the GSs and PANI. The electrical conductivity of GSs/PANI composite increases with the increase of the GSs doping quantity and reaches to 19.4 S/cm at the mass fraction of 25%, which almost equals to that of pure GSs (20.1 S/cm). The EMI SE increases with the frequency and the GSs doping quantity. When the mass fraction of GSs is 25%, the EMI SE increases about 42%, from 19.8 dB to 34.2 dB in the range of 2~18 GHz. Besides, the absorption proportion increases from 66% to 81%, which indicates that the GSs/PANI composite is the absorption-dominated EMI shielding material. These also prove that GSs are excellent filler of the PANI because of their special structure and properties. There will be a wide application prospects in the field of EMI shielding and microwave absorption.