Abstract: Vapor phase ethylation of catechol with diethyl carbonate as an alkylation agent was carried out under the catalysis of NaY loaded with K2CO3 or Mg(OAc)2. The catalysts prepared by vacuum impregnation were characterized by BET specific surface area measurement，temperature programmed desorption (NH3-TPD，CO2-TPD) and XRD. Both of the basic sites and the acid sites have important effects on the conversion of catechol. The basic sites are responsible for O-ethylation，while the acid sites are favorable for C-ethylation.