Based on the variation of dislocation density,which is influenced by rolling variables in hot strip-rolling process,ayield stress model was constructed.An integrated model was built to predict the temperature variation and microstructure evolution,in which the Orowan formula was used to calculate the stress and strain,and the finite difference method was adopted to determine the temperature field.This model was applied to predict the temperature variation,austenite grain size and phase transformation in hot strip-rolling process,and the prediction results are in good agreement with the measured ones on 2 050 mm continuous hot striprolling mill. Based on the variation of dislocation density, which is influenced by rolling variables in hot strip-rolling process, ayield stress model was constructed. An integrated model was built to predict the temperature variation and microstructure evolution, in which the Orowan formula was used to calculate the stress and strain, and the finite difference method was adopted to determine the temperature variation. This model was applied to predict the temperature variation, austenite grain size and phase transformation in hot strip-rolling process, and the prediction results are in good agreement with the measured ones on 2 050 mm continuous hot striprolling mill.