Nb2O5 nanowires and mesoporous Nb2O5 were used as the catalyst supports to prepare Pd/W-Nb2O5 and Pd/S-Nb2O5 which used in hydrogenation reaction of Cinnamicaldehyde(CMA) to hydrocinnamaldehyde(HCMA), the conversion and selectivity is investigated. Reaction was carried out using ethanol solvent, catalyst 0.1 g, 80 oC, 2 MPa H2 pressure, 6 h reaction time, Pd/W-Nb2O5 have a conversion about 99%, Selective of HCMA is about 65%. Under the same reaction conditions, Pd/S-Nb2O5 has a conversion about 98%, the selective is about 84%. Too more acidity sites on W-Nb2O5 surface cause more side reactions and low selective of HCMA. Reaction temperature, H2 pressure, thermal treatment temperature of the supports can influence the reaction conversion and selective. Increasing the temperature or H2 pressure can enhance the reaction conversion. But high thermal treatment temperature make the Pd/S-Nb2O5 lose the catalyst activity on account of higher crystallinity of Nb2O5 and lower acidity on the surface.