This work was studied on the Pd/CeO 2 used as catalyst for hydrogenation reaction in micro-reactor. A simple cerium complex for CeO 2 was prepared from cerium nitrate and triethanolamine in 1-propanol. The feasible structures of cerium complexes as four-coordinate and five-coordinate Ce-TEA complexes were determined by MS and FTIR. By calcining the Ce-TEA complexes at 600°C for 2h, the single phase of CeO 2 identified by XRD was obtained.Pd/CeO 2 , the hydrogenation catalyst, was prepared by doping palladium nitrate into the cerium complex before calcining at 600°C for 2h and investigated by XRD and SEM. The Pd-doped CeO 2 was preliminarily studied for catalytic hydrogenation of 4-cyanobenzaldehyde in a continuous-flow micro-reactor. Among all Pd/CeO 2 prepared, 10% Pd doped CeO 2 exhibited the greatest performance towards hydrogenation of 4-cyanobenzaldehyde in terms of the amount of hydrogenated products as 4-cyanobenzyl alcohol, 4-hydroxymethylbenzylamine, and 4-hydroxymethyltoluene.