Different concentrations of copolymer of (4-(acrylamido)-2-hydroxybenzoic acid) (AHB) with methyl methacrylate (MMA) were prepared and the reactivity ratio values of copolymerization were calculated using ¹H NMR and microanalysis techniques. Thermal analysis of the copolymers showed that the thermal stability are intermediate between poly(4-(acrylamido)-2-hydroxybenzoic acid) (PAHP) and poly(methyl methacrylate) (PMMA) homopolymers. Thermal degradation products of the PAHB were identified by GC-MS techniques. It seems that the mechanism of degradation of PAHB homopolymer is characterized by free radical formation followed by recombination along the backbone chain. The activation energies of the thermal degradation of the copolymers were calculated using an Arrhenius relationship