Abstract: An activated coke was modified by HNO₃. The influences of HNO₃ concentration, activation temperature, activation time and calcination temperature on surface properties the activated coke were investigated by orthogonal experiments. The SO₂ adsorption capacities of the modified activated coke were examined in a fixed bed reactor. The surface acidity-basicity, specific surface area and pore structure coke were characterized by acid-base titration, N₂ adsorption, iodine adsorption value and Fourier transform infrared spectrometry, respectively. The results show that HNO₃ modification raises the specific surface area and surface basicity of the activated coke. Calcination improves the surface basicity. HNO₃ modification obviously enhances the desulfurization performance of the activated coke.