Terpolymer resins (SOMF) were synthesized using salicylaldoxime, and melamine with formaldehyde in presence of hydrochloric acid as catalyst and using different molar proportions of salicylaldoxime, melamine and formaldehyde respectively. Its composition has been determined on the basis of the elemental analysis. The number average molecular weights have been determined by non-aqueous conductometric titration. Themogravimetric data was analysed to determine thermal stability of terpolymer and kinetic parameters were evaluated on the basis of thermogram of terpolymer. Freeman-Carroll and Sharp-Wentworth method have been used to calculate activation energy and thermal stabilities of these polymers. Kinetic parameters have been calculated using data of Freeman- Carroll method. the results obtained have been suitably discussed.