In this paper, we have shown modification of high-silicon zeolite ZSM-5 by zirconium, and the results of ethanol conversion on this catalyst. Effect of process parameters on the selectivity of ethanol dehydration products was analyzed. In addition, a mechanism of aromatic hydrocarbons formation including reactions of dehydrogenation, dehydrocyclization and alkylation of intermediates was discussed. It was found that with increasing temperature a selectivity decreased for reactions of isomerization and increased selectivity for aromatic products and products of cracking reactions. The data also confirms that hexene-1 is an intermediate in the conversion process of ethanol and the catalyst system with 1% Zr-ZSM-5 has a bi-functionality. Catalytic properties of the system in the conversion of hydrocarbons are determined by the presence on their surface of both Broensted and Lewis acid sites.