To improve workflow products, handling of the validity of information, temporal workflow is presented as a new concept by introducing time into workflow concept model as a dimension, which leads to time attributes being assigned to all workflow basic concepts and relationships between them. Based on the research on the expression and calculation of temporal information and the process meta-model of temporal workflow, through mapping the concepts in the meta-model into the elements of Petri Net, a temporal workflow process model, TPWF-net, is presented, which can describe the process, resource, case and their time attributes in one model synthetically. Then, some theorems are proved, which include structural equipollence between TPWF-net and WF-net, and the soundness of free-choice synchronal TPWF-net. It is also proved that well-structured TPWF-net can be decided in polynomial time. Finally, a structured modeling method of TPWF-net and a structure-simplified method of model verification are presented. Temporal workflow makes it more comprehensive to describe and analyze the time-related problems in workflow area. A temporal workflow engine prototype based on TPWF-net has been implemented and applied in some projects supported by local government.