A catalytic conversion of ethanol to propylene was carried out using H-ZSM-11. The highest propylene selectivity was obtained at Si/Al2 ratio of 120 and the value was 25% at 0.1 MPa, 550 °C. In W-modified H-ZSM-11, the ethylene production by the dehydration of ethanol was promoted by higher W/Al2 ratio, whereas C4 formation by the oligomerization-cracking was slightly decreased with an increase in the W/Al2 ratio. When the W/Al2 ratio was 1.0, 23% and over of propylene selectivity was kept for over 16 h at 500 °C. A rapid increase in ethylene formation was also depressed. W-modified H-ZSM-11 with Si/Al2 ratio of 120 was found to be highly effective for the conversion of ethanol to propylene.