Atom-transfer radical polymerization (ATRP) is a powerful controlled radical polymerization technique for material synthesis with specific properties. Since the emergence of this technique, few studies have been made to develop kinetic models to study the system at high temperatures. This paper presents a new approach of ATRP kinetic modeling: inclusion of some break reaction common at temperatures above 100 A degrees C aiming to make the model more robust to simulate the process at high temperatures. Kinetic modeling was developed by material balances and the method of moments. It was demonstrated that for the styrene ATRP at 110 A degrees C a better reproduction of experimental data was obtained by the modeling proposed in this work, with a reproduction percentage error for conversion of 4 % versus some values higher than 10 % for the common models from the literature. The model proposed in this present work could help future works dealing with analysis of temperature effect, optimization and process scale-up, since it takes into account some common chemical reactions at higher temperature.