A series of Pd/SiO2 and Pd.Ti/SiO2 catalysts were prepared by the incipient wetness impregnation method. The catalytic performance for selective hydrogenation of acetylene to ethylene was measured under ‘‘high concentration acetylene’’, ‘‘high space velocity’’ and ‘‘no dilution gas’’ conditions. The crystal structure and particle size of the catalysts were characterized by the X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), nitrogen physisorption using the BET method and transmission electron microscope (TEM). The results showed that the titanium oxide in Pd.Ti/SiO2 catalyst was amorphous and the addition of Ti reduced the particle size of Pd significantly. Comparing to the Pd/SiO2 catalyst, the ethylene yield increased from 64.1% to 88.3% under Pd.Ti/SiO2 catalytic system.