Abstract: In this paper,the influences of solvents, monomer conncentration and initiator concentration on radical polymerization of N -vinylpyrrolidone(NVP) are investigated. Especially, benzene, ethanol, distilled water are experimented as solvents to investigate the influences of solvent polarities, viscosities of mixture of monomer and solvent on polymerization rate, chain propagation rate and relative molecular mass of polyvinylpyrrolidone. Furthermore, crosslinking polymerization properties of N -vinylpyrrolidone and N,N - methylenebisacrylamine(NNMP) are studied. It is found that a higher yield of crosslinking polyvinylpyrrolidone(PVPP) can be obtained in a aqueous solution of some inorganic salt. Some explanations are presented.