A series of AIPO(4)-MoO3 (APM) systems with various molybdena loadings (5-50) mol%, same modified with phosphomolybdic acid (PMA) and cerium ions, were prepared by an impregnation method and calcined at 400degreesC, except for the samples modified with PMA which were calcined at 350degreesC for 4 h. The catalysts were characterized by TG/DTG, XRD, IR spectroscopy, N-2 adsorption and electrical conductivity measurements. The surface acidity and basicity of the catalysts were determined by adsorption of pyridine and the dehydration-dehydrogenation of isopropyl alcohol. The catalytic esterification of acetic acid with ethanol was carried out in a convention fixed bed reactor. The results clearly revealed that the catalyst with a composition of 10 mol% MoO3 (APM10) was the most active and selective catalyst for the production of ethyl acetate. Moreover, the yield of ethyl acetate increases on addition of PMA into APM10 while it decreases on the addition of Ce4+ ions. These results were correlated with structure, semiconductivity and the acid-base properties of the prepared catalysts. (C) 2003 Society of Chemical Industry.