Abstract Market economy is the contract economy. Contract is the bridge and link to take economic activities and get economic benefits for the enterprise. As one of main market bodies, the construction enterprise is hound to contract and normalized by Contract Law from bidding for a project to signing a contract ,from execution of the contract to project claims and from clearing of construction cost to treatment of contract disputes. Only are the characteristics of contract deeply understood,the flexible application of Contract Law can he made. This paper proposes the notable issues in the practice of execution of contract and Contract Law based on the description of a contract and its characteristics, which has guidance significance for correcting problems related to the contract in the complex economic activities by construction enterprise.