Several Pd-based bimetallic catalysts, Pd/Co, Pd/Ni and Pd/Cu, were synthesized by replacement reactions. The catalysts were characterized by XRD and CO chemisorption and their catalytic properties were evaluated using cyclohexene self-hydrogenation. The results suggest that the high catalytic activity of Pd/Ni is most likely due to the monolayer-dispersion of Pd on the Ni surface. The results also suggest that Pd is monolayer-dispersed on the Co surface in Pd/Co, whereas Pd forms surface alloy or solid solution with Cu in Pd/Cu.