AbstractOligo‐ethylene/propylene glycol ethyl ether acetate (oligo‐EGEEA and oligo‐PGEEA) used to be synthesized in a two‐step process with acetic acid as starting material. This paper describes a one‐step production process catalyzed by the AlMg composite oxide, achieved by alkoxylation of ethyl acetate directly. Aiming at a narrow adduct distribution to get high product selectivity of mono‐derivatives, the alkoxylation parameters, such as the Al/Mg molar ratio of the catalyst, molar ratio of reactants, temperature, initial reaction pressure, and reactant feed rate were investigated. The highest content of mono‐ and di‐derivatives in the products was: w (oligo‐EGEEA) = 73.8%, w (oligo‐PGEEA) = 87.9%, respectively. The product selectivity of mono‐EGEEA was decreased by only 5% after reusing the catalyst for ten runs. A 1.26‐fold increase in the yield of mono‐PGEEA was achieved by treating the catalyst surface with alcoholic potash. Copyright © 2006 Society of Chemical Industry