Kinetic studies for the nucleophilic substitution reactions of benzyl halides(para-substituted benzyl bromides and benzyliodide) with substituted pyridines in MeOH-MeCN mixtures have been carried out in order to elucidate the reaction mechanism. Cross interaction coefficient, ${ ho}_{XY}$ values suggested that the reactions between benzylhalides and substituted pyridines exhibit an dissocitive $S_N$2 mechanism. Hammett (${ ho}_X$, ${ ho}_Y$), Br${o}$nsted ${eta}_N$ and solvatochromic correlation coefficient a, s, a/s values were illustrated. Kinetic results were compared between potential energy surface model and quantum mechanical model. The quantum mechanical approach showed to be consistent with kinetic results.