Quantitative structure-property relationships (QSPR) studies were performed for kinetic chain-transfer constants of 90 agents on styrene polymerization at 60 degrees C. By using stepwise multilinear regression analysis (MLRA) and artificial neural network (ANN), linear and nonlinear models containing seven descriptors were obtained with R(2) of 0.7866 and 0.8661 for the training set, respectively. The reliability of the proposed models was validated through the test set. The descriptors involved in the models are related to the molecular conformational changes and some functional groups. As these descriptors are directly calculated from the molecular structure, the proposed models can be employed to estimate the chain-transfer constants for styrene. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 356-364, 2012