A series of mordenite zeolites with different morphologies were synthesized via a facile organic-free hydrothermal route, and characterized by X-ray diffraction, scanning electron microscopy, X-ray fluorescence spectrometer and N(2) adsorption-desorption techniques. Influences of synthetic parameters, including seed crystal, silicon precursor, SiO(2)/Al(2)O(3), Na(2)O/SiO(2) and H(2)O/SiO(2), on mordenite crystallization were investigated systematically. It was found that mordenite zeolites with various morphologies, such as fiber-like, rod-like, prism-like and needle-like ones could be synthesized in control. Especially, novel nano fiber-like MOR crystals with high c/b aspect ratio were prepared from low silica concentration system, which was manipulated by using small initial SiO(2)/Al(2)O(3) ratio, large H(2)O/SiO(2) and silicon source with slow dissolution rate. Moreover, mordenite samples with various morphologies exhibited different mesopore property and thermal stability. (C) 2011 Elsevier Ltd. All rights reserved.