Mesoporous, self-assembled Pd nanopsheres have been prepared in the organized micellar template, sodium n-dodecyl sulfate (SDS), of which electrostatic regulation was adjusted by adding H + ions. In this study, the diameter of self-assembled nanospheres can be controlled from ∼41.5 to ∼56.2 nm by the concentration of palladium ions added. As supported by the analysis of quartz crystal microgravimetry (QCM) and mixed potential theory, the mesoporous nanospheres can be successfully used as activators and have the excellent activity for electroless nickel–phosphorous depositions (EN pD). A comparison of deposition rate with a system of Pd nanospheres, the Pd nanosphere with small size was found to exhibit maximum activity toward oxidation of NaH 2PO 2, reducing agent of EN pD.