Abstract: The developments of temperature distributions were studied for thick polymeric matrix composites. The finite element formulation of the transient heat transfer problem was carried out for the composites based on the heat transfer differential equations with non-linear internal heat sources. The finite element analysis software, which was based on the general finite element software package, was developed for numerical simulation of the entire composite cure process. Two kinds of thick polymeric matrix composites cure processes were analyzed by the finite element software. It was found that the cure process which was used to cure common composites was unfit for thick composites.