The capability of sol-gel and conventional precipitation techniques for the synthesis of nanocrystalline γ-alumina was investigated.These catalysts were used for vapor-phase dehydration of methanol to dimethyl ether in a fixed-bed reactor under the same operating conditions (T= 300℃,P=1 bar,LHSV = 2.8,11.7,26.1 h-1)and characterized by means of N2 adsorption-desorption,NH3-TPD,XRD,TGA and SEM techniques.According to the experimental results,the catalysts prepared using sol-gel method in non-aqueous medium showed better performance compared with those prepared by other methods.