Abstract: This paper presents a new method for constructing the project network and its computer program. The input data of this program are the sequence and duration of activities. The outputs include the right numbering of the nodes, time of events and activities, key route and network diagram, By the use of this program, the flow chart of a project can be automatically transformed into network with minimum dummy activities. The results of constructing about 110 project networks with this program show that this method is available for all kinds of project network construction and can increase the efficiency of the project planning work.