Protonated ZSM-5 type zeolites containing alkaline earth metals (M-HZSM-5. M: alkaline earth metal) were prepared under various synthesis conditions and their catalytic performance in the conversion of ethanol to light olefins, especially propylene (C3H6), were investigated in detail. The C3H6 yield and the catalytic stability were strongly dependent on M/Al and SiO2/Al2O3 ratios as well as on the reaction conditions. Among M-HZSM-5 zeolites, the Sr-HZSM-5 zeolite having a SiO2/Al2O3 ratio of 184 and a Sr/Al ratio of 0.1 exhibited the highest C3H6 yield of ca. 32 C-% and a high catalytic stability at the reaction condition of 500 degrees C and W/F value of 0.03 g(cat)/ml/min. (C) 2010 Elsevier B.V. All rights reserved.