Vinyl acetate and itaconic acid copolymers, obtained by radical copolymerization using single and continuous methods of itaconic acid addition, the amount of the acid being up to 8.5 mol %, were characterized by DTA, TG, DTG, and DSC. Using IR spectroscopy for both types of copolymers, it was proved that cyclodehydration takes place in the temperature range 130–230°C. In the range 230–350°C, processes of decarboxylation of cycloanhydrous and carboxylic groups and splitting of acctic acid proceed at the same time, followed by destruction of the polyene structures formed. The rate of thermal degradation depends both on the amount and distribution of itaconic units in the macrochain. The kinetic parameters of the process were calculated.