Two novel polyelectrolyte complexes (PEC) have been synthesized using pendant type imidazolinium organosilicon copolymers with poly(sodium styrene sulfonate). These PEC dissolved in a ternary solvent system and displayed high thermal stability. Turbimetry and conductometry measurements showed PEC formation to be a stoichiometric reaction. The formation of PEC was decreased with increasing polyion concentration and organic solvent, but decreased with decreasing dielectric constant of the solvent.