Under atmospheric pressure, nano-polyethylene fibres were prepared via in situ ethylene extrusion polymerization, with MCM-41 and SB-A15 supported zirconocene dichloride (Cp2ZrCl2) catalytic systems, respectively. The effects of the geometrical structures and surface properties of MCM-41 and SBA-15 on the morphology of the resultant polyethylene, catalytic activity and polymerization rate were investigated and compared in various polymerization conditions. The possible formation mechanism of nano-polyethylene fibres with MCM-41 and SBA-15 supported Cp2ZrCl2 as catalyst was discussed. (c) 2005 Elsevier B.V. All rights reserved.