A method for calculating the temperature distribution in the polymer sample during DSC measurements was proposed in this paper based on the one-dimensional heat conduction equation and Tools-Narayanaswamy-Moynihan (TNM) model.It was found that the temperature lag increased remarkably with increasing sample thickness and heating rate.A maximum temperature difference between the center and the surface of a PS sample with 1.0 mm thickness was calculated to be 0.882 K when it was heated at a rate of 10 K/min after cooling at 1 K/min.Meanwhile

a method for calculating the sensible heat capacity of the polymer with different thicknesses after different thermal treatments was proposed.The theoretical results were consistent with the experimental data.