A series of supported MoO3 catalysts were prepared by an equivalent-volumetic impregnation method with MoO3 loadings ranging from 1 to 30 wt%, with SiO2 and Al2O3 as the carrier. The samples were characterized by X-ray diffraction (XRD), specific surface area measurements (BET), temperature-programmed desorption (NH3-TPD). The catalytic esterification of acetic acid with ethanol was carried out in a three-neck flask at 90-100℃.The results clearly revealed that MoO3/SiO2 and MoO3/Al2O3 catalysts were active and selective towards the formation of ethyl acetate. The MoO3/SiO2 catalyst containing 5 wt% MoO3 was the most active and selective one. The results emphasize the importance of the porous structure together with the weak acidic sites of the prepared catalyst towards ester formation.