Because of the development of the regularization, standardization, marketization of project bidding and tendering, and considering of the significance of bidding to construction corporations, a project bidding decision support system is developed supported by forecast theory, decision-making theory, game theory and computer science. The system is based on the practical flow of project bidding and the whole process. The paper discusses the structure, the function, the technologies that make the system comes true and the application of the system. The system can help construction corporations in consultation of information, selecting project, establishing the total price and interior adjusting of bidding price, presenting standard bidding report.