The incorporation mechanism of SiO2 particles into zinc electrodeposit is discussed. The SiO2 particles precipitate in two ways on the (00-1)(eta) of zinc electrodeposit: by lined up particles along the laterally growing macrosteps on the (00.1)(eta) and by randomly dispersed particles on the (00.1)(eta). These particles incorporate into the electrodeposits by following two processes. The sidewalls of particles are incorporated into the macrosteps at the edge of (00.1)(eta). The bottom of randomly dispersed particles are incorporated into the (00.1)(eta) probably by the atomic steps.