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The migration of silica nanoparticles in the laminated sheets of poly(butadiene) (BR) and poly(styrene-co-butadiene) (SBR) rubbers is investigated. Laminated rubber sheets are subjected to various annealing conditions beyond their glass transition temperatures. After separation, the surface morphologies of separated sheets are observed by scanning electron microscopy. The transfer of particles occurs from SBR to BR during annealing, but not from BR to SBR. Since SBR exhibits a higher viscosity than BR under the experimental conditions, the transfer direction is determined by interfacial tension. Silica particles without any surface modification prefer to reside in BR. The diffusion distance is predicted from the Stokes-Einstein equation. Differential scanning calorimetric measurements show that BR crystallization is enhanced by the silica particles immigrated from the SBR sheet, because of their favorable nucleating ability. This study allows the prediction of silica particle localization in BR and SBR blends.