The atom density profile, structure and diffusion behaviors of dense carbon dioxide fluid in clay-like slit pores have been studied by molecular dynamics simulation at 308.2 K. CO2 molecules form distinct layers in the proximity of the pore surfaces. The orientational distribution and radial distribution functions of the confined CO2 molecules are presented in order to obtain the microscopic structure of the interlayer fluids. The self-diffusion coefficients and the orientational correlation functions of the confined CO2 have also been calculated and compared with those of bulk CO2 fluid. (c) 2005 Elsevier B.V. All rights reserved.