The thermal stabilities of poly(beta-methylhydrogenitaconate-co-2-methyl-2-oxazoline) and poly(beta-methylhydrogenitaconate-co-2-ethyl-2-oxazoline) obtained by spontaneous copolymerization have been studied by programmed thermogravimetric analysis over the temperature range from 293 K to 773 K under a flow of nitrogen. Most of the copolymers do not show weight loss until 473 K and they degrade in one step. The kinetic parameters Ea, n and A were obtained following one method of thermogravimetric analysis. The reaction order for all copolymers was 1.0. The poly(beta-methylhydrogenitaconate-co-2-methyl-2-oxazoline)s were the most thermostable copolymers.