Abstract: The molar mass distribution was investigated at the hydroxyethylation of aralkyl alcohols (benzyl-, β-phenyl ethyl and γ-phenylpropyl) in the presence of conventional homogeneous and a heterogeneneous catalyst, K 10. While the widely used NaOH and SnCl4 catalysts gave the expected results in molar mass distribution (with base it is of Weibull-Nycander-Gold type, with the Lewis acid of Flory type). The K10 caused a narrower Flory type distribution which is effected by the length of alkyl chain in the aralkyl alcohols and by the modification of the pure K10 with metal ions (CU+2 and Fe3+). By this way with a substrate and hydroxyethylation can be achieved.