Hydroxyethylation is one of the most important reactions in the production of nonionic surfactants R-X-H + v EO ------------------------- R-X-(EO)vH EO = ethylene oxide (or glycol unit ), R = base material , X = O, S, NH, CO2 ………etc. These material can be characterized by the amount of EO reacted (the average degree of Ethoxylation) and by the concentration of the individual homologues in the reaction mixture (the molar mass distribution) The aim of this work was the preparation and characterization of hydroxyethylated aralkyl alcohols with different types of catalysts, and the investigation of the effect of reaction conditions on the molar mass distribution.