The equilibrium constants and other thermodynamic parameters for the adduct formation between cis-[Pt(p-Tol)2(SMe2)2] complex as an acceptor and 3-hydroxy pyridine (pyridine-3-ol) ligand as a donor in acetone, ethanol and benzene at various temperatures (13-20°C) have been spectrophotometrically measured. Our studies showed that ΔH°(KJ.mol-1) of the reaction in ethanol, acetone and benzene are 6.442, 43.1 and 46.247 respectively. The related entropies (J.mol-1.K-1) have been obtained 89.82, 218.5 and 236 respectively, too. In addition, the amount of ΔG°(kJ.mol-1) for the reaction occurred in solvents mentioned above are -20.324, -22.013 and -24.081.