A contractor refers to a construction enterprise that has certain production capacity, technical equipment and working capital, has the business qualification of contracting construction tasks, can provide different forms of construction products according to the requirements of the owners in the construction market, and obtains the project price. According to their main forms of production.

It is divided into survey and design units, construction and installation enterprises, manufacturers of precast concrete components and non-standard parts, commercial concrete supply stations, construction machinery leasing units, and enterprises specialized in providing labor services. According to their different contracting methods, they are divided into construction general contracting enterprises, professional contracting enterprises and labor subcontracting enterprises.

sometimes referred to as the contracting unit, the construction unit (Building Law) or the owner and the project legal person.

first, about the qualification of the project contracting party. "Building Law" does not limit the qualification of the project contracting subject. Therefore, the employer can be a state organ, institution, enterprise legal person and social organization with legal personality, or a registered individual partnership, individual business households and other natural persons with civil capacity, or other organizations without legal personality.

second, the ability to pay the project price. It is an obligation stipulated by law for the employer to pay the project price, and the employer should have the ability to pay the project price.

thirdly, the legal successor refers to the unit merged or separated with the employer, including the unit that merged with the employer, and the units and individuals that purchased the employer's contract and accepted the assignment from the employer.