Ru-Zn/MCM-41 catalysts for the partial hydrogenation of benzene with differing Zn contents were prepared by the incipient-wetness impregnation method. The evaluation results indicate that Zn simultaneously depresses the catalysts activity and cyclohexene selectivity. This can be attributed to the change in the amount of the different hydrogenation sites affected by Zn. The weak hydrogenation sites can promote benzene conversion, and the strong hydrogenation sites, a novel kind of hydrogenation site found on the surface of the catalysts under the influence of Zn, are beneficial for cyclohexene hydrogenation.