Abstract: The project investment of the petroleum construction is influenced by many risk factors including the external risks of resources , market , finance , society , nature , economy and policy , and the internal risks of completing a project , administration , technical and human : founding the system of comprehensive evaluation targets and weigh of the petroleum project investment , reasonably using the many factors model of the fuzzy
comprehensive evaluation , going on the quantity analysis and comprehensive evaluation about the risk factors , and calculating them which contract with largeOscale petroleum project realizes scientifically evaluation and decision of the risks of the petroleum project investment .

Key words: petroleum project, investment risk, comprehensive evaluation