Interfacial-initiated microemulsion copolymerizations of Styrene (St) and N-vinylpyrrilidone (NVP) by the redox initiation couple of cumene hydroperoxide (CHPO) and the presence of the base tetraethylenepentamine (TEPA) were carried out using Tween-80 and n-butanol as the surfactant and co-surfactant, respectively. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were recorded to analyze the chemical composition of latex particles. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to observe the particle morphology and dynamic light scattering (DLS) to determine the particle size. The results demonstrated that interfacial-initiated microemulsion polymerization prompted the copolymerization of water-soluble NVP monomer with oil-soluble St monomer to form core-shell nanoparticles by one-stage.