An access to an increase in the information storage capacity is to reduce memory units to a nano-scale. There fore, we used carboxylized phenyl-capped polyaniline tetramer (PCAT) as the functional component and silica as the carrier to prepare PCAT/silica composite nano-particles (= 60 nm) with a structure of core-shell. The functionalized particles were two-dimensionally arrayed on substrates such as silicon, glass and ITO glass at pH 3.SEM and AFM results proved the arraying regularity of these particles under any given conditions, and the electrostatic force microscopy showed their response to +3 V bias applied.