Soy protein concentrate, a biodegradable renewable resource agricultural biopolymer, has been cross-linked with formaldehyde for better processing material. Thermogravimetric analysis of the biopolymer has been followed using a computer analysis method, Lotus package, developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The mechanism of degradation of the biopolymer is explained on the basis of the kinetic parameters.