The phenomenon of White-Black Project Contract extensively exist in the building market of our country, and leads to negative results such as default of construction debt layer upon layer, low project quality, and disorder of building market, which restrict the healthy development of building market in our country severely.

On employer s self breaking right of construction contracts;

Because of the particularity of construction and not defining the construction contract clearly, it is confused between the real right ascription of construction and the ascription of intellectual property right produced in construction.

In this paper, a general survey of the system of construction contract is carried out.

The contract provisions are not standard and litigant both sides do not have strong legal consciousness, all of these make many disputes in engineering construction contract.

In this paper,the necessity of the uses of implied terms system of contract in domestic construction contract is pointed out,the main contents of the implied terms of contract about contractor s key obligations in construction contract are analyzed and studied.

The enforcement of the legal relief right of construction contract,not only need to meet the strict limited condition in law,but also need to follow corresponding due course and method of law.