Ruthenium nanoparticles entrapped in periodic mesopolymers, Ru/FDU-15-H-2, were proved to be an effective and reusable catalyst for the liquid-phase hydrogenation of benzaldehydes, affording a constant activity after the 6th cycle in water. Besides the hydrogenation of benzaldehydes, Ru/FDU-15-H-2 catalyst can also catalyze the liquid-phase hydrogenation of arenes, olefins and other carbonyl compounds under mild conditions.