Titania-supported iron oxide catalyst has been designed based on a geometric consideration. The catalyst prepared by reducing the precursor obtained from incipient wetness impregnation in H-2 at proper temperature exhibits good activity (CO2 conversion >24%) and selectivity (> 60%) in the selective synthesis of hydrocarbons (C-2-C-5) from CO2 and H-2. The catalytic activity has been found to vary with iron weight loadings in a "twin maxima" fashion and, also, to be affected by the reduction temperature. Mossbauer and EXAFS analyses suggest that the active phase is coordinatively unsaturated ferrous cations associated with alpha-Fe. Alternative arrangement of the two phases in a proper way is beneficial to relax the Fe-O bonds and results in the highest catalytic activity for the catalyst, but the formation of predominantly FeTiO3 phase finally makes the catalyst inactive.