This paper introduces the basic content of information asymmetry theory and comments on the theory of information asymmetries.It establishes an information model in project management and analyzes the phenomenon of information asymmetries between owner and contractor in the phase of bidding and fulfilling.It presents some countermeasures of resolving information asymmetries in the project management such as building information network,devising reasonable contract,reinforcing government' s guidance,strengthening the good faith,breeding intermediate agency,building the system of early risk warning and so on.