The adsorption and diffusion of 1-butene in purely siliceous MCM-22 zeolite have been studied by the grand canonical Monte Carlo and molecular dynamic simulation. The adsorption behavior of 1-butene was explored in detail from adsorption sites, interaction energies. The mass clouds show that 1-butene can be adsorbed freely in MCM-22 zeolite, and adsorbed preferentially in 10-MR (member rings) channel system with high interaction energy. The diffusion characteristic for 1-butene in two independent channel systems was investigated by using molecular dynamic simulation. The results were obtained by analysis the trajectories of diffusion and the diffusion coefficients, which shows that a large diffusion for 1-butene in both channel systems, especially in the supercage system. The adsorption and the diffusion of the hydrocarbon molecules were affected by the different sizes and structures of 10-MR and 12-MR in MCM-22 zeolite. Moreover, the positions where the molecules are expected to react were revealed. (C) 2009 Elsevier B. V. All rights reserved.