A polystyrene‐block‐poly(2‐vinylpyridine) (PS‐b‐P2VP) micellar structure with a P2VP core containing 5 nm CdS nanoparticles (NPs) and a PS shell formed in toluene that is a good solvent for PS block undergoes the core‐shell inversion by excess addition of methanol that is a good solvent for P2VP block. It leads to the formation of micellar shell‐embedded CdS NPs in the methanol major phase. The spontaneous crystalline growth of Au NPs on the CdS surfaces positioned at micellar shells without a further reduction process is newly demonstrated. The nanostructure of Au/CdS/PS‐b‐P2VP hybrid NPs is confirmed by transmission electron microscopy, energy‐dispersive X‐ray, and UV‐Vis absorption.
