The alumina microfibers with mesoporous structure were synthesized by a facile hydrothermal and thermal decomposition route. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED and N-2 adsorption-desorption measurement. It was shown that the length and diameter of these alumina microfibers are about 10 mu m and 300-500 nm, respectively. All these alumina microfibers prepared by the PEG templates with different molecular weight have the different high surface area but nearly the same pore diameter about 3.5 nm. The calcination experimental result shows that the mesoporosity of these alumina microfibers can be maintained even at 1373 K. On the other hand, the higher selective catalytic reduction (SCR) of NO effectiveness present that the as-obtained mesoporous alumina have stronger adsorption property because of its high surface area. (C) 2009 Elsevier B.V. All rights reserved.