A nondestructive inverse method is developed to determine the internal temperature distribution of PEMFCs. In this study, attention is focused on global measurement for the irregular temperature distribution at the interface between the carbon plate and the membrane electrode assembly (MEA) based on the measured temperature data on the outer surface of the end plate. In this report, a concept of point-by-point temperature prediction is adopted. This approach is particularly suitable for determining an irregular temperature distribution that is difficult to handle by the existing polynomial-function approach . A number of test cases are considered in this study. Three irregular temperature functions are specified and regarded as exact temperature distributions for testing the performance of the approach. Influence of the uncertainties of the measured temperature data on the outer surface and the number of the temperature prediction points (NXxNY) on the end plate surface is evaluated. In addition, the effects of the initial guess on the uniqueness of the predictions are also investigated.