The conductance data of sodium diethyldithiocarbamate (NaDDC) in water solutions at various temperatures (25, 30, 35 and 40°C) are presented. The results were construed by applying the Fuoss-Onsager equation to obtain the parameters: equivalent conductance at infinite dilution (Λo), the distance of closest approach (å) and association constant (KA). In the light of the solvent separated-ion pair model, the KA trend is discussed. A comparison was done between the value of å and the sum of calculated electrostatic Stokes' radii R+ and R-. Both of thermodynamic functions (ΔHo, ΔGo, ΔSo) and the activation energy (ΔEs) were determined; the Λo values were noticed to increase gradually with the dramatic increase in temperature referring to less solvation or higher ions mobility. Negative values of Gibbs free energy change ΔGo for (NaDDC) indicate that the association process is preferable than the dissociation process. The positive value of (ΔHo) points to that the association process is endothermic. Entropy change (ΔSo) values were positive which means that the solvation of ion-pair decreases emulated to that of the free ion.