Poly(1-butyl-3-vinylimidazolium bromide) is a polymerized ionic liquid (PILs), a relatively new class of materials that combines the attractive properties of ionic liquids (ILs) and polyelectrolytes and finds wide applications. The backbone of this PIL is composed of quaternary imidazolium salts, which are among the most promising and popular ILs. However, little is known about the physicochemical characteristics of the aqueous solutions of this PIL. In this study, we synthesized and characterized samples of this PIL and obtained experimental data on the viscosity, static and dynamic light scattering, and nuclear magnetic resonance diffusometry for aqueous and aqueous KBr solutions with varying polymer contents at T=298.15 K. We discuss the effects of the polymer concentration and salinity on the behavior of the solution.