Abstract: It is difficult to simulate precisely the temperature field in plate rolling process and the precision of commonly used temperature models are not high. So, a quadratic curve temperature model is developed to computer the temperature field on plate. Based on it, the plate rolling process is simplified to a certain degree to approximate the quadratic curve to the real temperature field along the thickness of plate. Thus, a specific quadratic curve model is obtained with relevant computation method provided. The model has been applied to the temperature field in the rolling process of the Q235A steel slabs. The result indicates that the relative error is within 3%, if using the model to predict related temperatures, which can meat satisfactorily the requirements for on-line plate rolling. The model can also play a role as example in analyzing and controlling other temperature fields in hot rolling.