Poly(vinylpyrrolidone) (PVP) is solube in water solution. PVP is interesting from bilolgical viewpoint, since it has structrural feature similar to those of proteins. Indeed, even in its actual behavior it also shows similarities to proteins. The properties of dilute aqueous solutions of PVP in the presence of ureas(urea, 1, 3-dimethylurea, 1, 1, 3, 3-tetramethylurea) are studied by measurements of intrinsic viscosity,[$\eta$] at 20$^\circ$C. These result are discused on the basis of the nature of the side group interaotion with the solvent and cosolute. It would seem that two types of interactions play an important role at the solution: The first is hydrophobicity increased by increasing methyl groups of ureas and the second is hydrogen bonding in which hydrogen attached by nitrogen of urea can interact with an amide group of PVP. The role of the preferential adsorption of one of the cosolutes on the polymer was also considered.