A novel method, situ polymerization stringed assembly (SPSA), is proposed to prepare stable solid or hollow supramolecular polymer particles, which are assembled by numerous nanoparticles. By this method, the fabrication of primary nanoparticles (poly(methyl methacrylate), PMMA), the linkers (polyvinylpyrrolidone, PVP, chains) between the nanoparticles, and the final assembled solid or hollow particles could be achieved in just one-pot by methyl methacrylate (MMA)/N-vinylpyrrolidone (NVP) microemulsion polymerization under UV irradiation. The structures of the supramolecular particles can be changed from solid to hollow by tuning the mass ratio of MMA/NVP in the microemulsion. AFM, TEM, and SEM experiments are performed to identify the results.