This research investigates the thermal shock resistance behavior of a plate subjected to a sudden thermal load. It contains two parts. In Part I of this research, the nonlocal elastic theory is implemented to obtain the thermal stress and strain fields of the plate. The difference between the nonlocal model and the local model is discussed. It is found that the thermal stresses are highly over estimated by the local model, which ignores the effect of small length scale. The phenomenon indicates confirms the fact that introduction of non-local parameter is essential in the evaluation of thermal stresses of solids. � 2014 WIT Press.