The conditional dissociation constant (K_c) and thermodynamics dissociation constant (K_d) are use in solution chemistry to measure the extent of dissociation of molecules in solution. The thermodynamics dissociation constants of pyruvic acid were investigated using the principle of conductivity measurements in water (0:0), Sodium Chloride (1:1), Sodium Sulphate (1:2) and Lanthanum Chloride (3:1) supporting electrolytes in water as solvent. The degree of dissociation of pyruvic acid was determined through the measurements of molar conductance at specific dilution and molar conductance at infinite dilution. The degree of dissociation being a parameter through which the conditional and thermodynamic dissociation constants were determined was found to decrease with increase in concentration. The thermodynamics dissociation constant (K_d) was observed to increase with increase in charge ratio of the supporting electrolytes except, for lanthanum chloride which may possibly due to non participation of the hydrated lanthanum ions. The result revealed that in water(0:0) electrolyte, the K_d is 1.48 x 10^-4 /moldm^-3, in 1:1 electrolyte the K_d is 1.51 x 10^-4/moldm^-3, in 1:2 electrolyte the K_d is 1.62 x 10^-4/moldm^-3 while in 3:1 electrolyte the K_d is 0.79 x10^-4/moldm^-3. The change in ionic strength of the electrolytes was found to influence the values of thermodynamic dissociation constants of pyruvic acid in various supporting electrolyte as obtained.