Abstract The concentration and temperature dependences of the reorientational correlation times of nitrobenzene in solutions of tetraethyl (TEABr) and tetrabutylammonium bromides(TBuABr) have been determined by Raman line shape analysis. Pure liquid nitrobenzene was evaluated for comparison. The reorientational correlation times of nitrobenzene in solutions decreased with increasing concentration of the salts and the apparent activation enthalpy of τor of nitrobenzene in solutions was larger than in that pure nitrobenzene. From the experimental results, the solution structure of TEABr and TBuABr in nitrobenzene are discussed.