Classical molecular dynamics simulations have been used to investigate the absorption and diffusion behavior of polyethylene (PE) chains on the surface of the side-wall of the carbon nanotube (CNT). Different degrees of polymerization from 50 to 80 at separate temperatures of 300, 400, 500, and 600 K are considered. Through the simulation, it is examined that the PE chains are absorbed on the surface of CNT and form stable composites with the nanotube as capsules. It is found that the most probable distance between the CNT and the C atoms in backbone of PE molecules only attribute to the temperature, and at T = 300 K, this distance is about 3.8 angstrom. Furthermore, the pattern of the composites mainly depends on the temperature and the length matching of the chains and the CNT. In particular, the PE chains keep approximately linear conformation, and extend along the axis of the CNT at the room temperature. (C) 2007 Wiley Periodicals, Inc.