In order to ensure the smooth achievement of aided road section Ⅰ from Dukou to Xinshi in Jinshajiang Xiluodu water power station,discusses on how to do well in road project contract management from rationality of contract,fix of contract types,rational division of risks for both parties and the timely process of contract changes,aims at reducing project cost and improve the economic benefits.

This article used the manageable risk-sharing ideas and contractual Economics ideas to study the principle of project risk sharing and contract change in model contracts and CONS from the point of contractual Economics.

Taking the performance as an objective,and evaluation indexes as criterions,this paper constructs a hierarchical structure to put in order the performance corresponding to each contract change,so as to analyze the influence of the contract changes on the performance.

The opportunism and asymmetric of information, gives birth to hold up, low-investment and moral hazard with hidden information between owner and contractor in the contract variation.

This paper,from the Employer s viewpoint,predicts and analyzes the reasons and risks for contract variations in the process of contract performance,and puts forward some specific preventive measures and countermoves.

Research on optimal construction contract in connection with contract variation;