Contract law divides contracts into 15 categories, including: sales contracts; Supply electricity and water; Gas and heat contracts; Gift contract; Lease contract; Financial lease contract; Contract; Construction project contract; Contract of carriage; Technical contract; Custody contract; Warehousing contract; Entrustment contract; Subject contract; Intermediary contract.

There are other classifications in contract law, including:

(1) Planned and unplanned contracts The planned contracts are contracts signed according to the relevant national plans; An unplanned contract is a contract concluded by the parties according to market demand and their own wishes. In today's market economy, although the proportion of contracts concluded according to the plan has been greatly reduced, there are still some contracts concluded according to the relevant national plans. The relevant legal persons and other organizations of this plan contract shall conclude the contract in accordance with the obligations stipulated by relevant laws and administrative regulations.

(2) Unilateral contract and bilateral contract A unilateral contract refers to a contract in which both parties do not enjoy rights and obligations, such as a gift contract. A bilateral contract is a contract in which both parties enjoy rights and obligations, such as a construction project contract. Most contracts are bilateral.

(3) Non-commitment contract and customary contract A non-commitment contract is a contract that can be established with the consent of the parties. A customary contract is a contract that requires the parties to deliver the subject matter or other payment obligations on the basis of their consent. Most contracts are agreed contracts, the purpose of which is to determine the effective date of the contract.

(4) Master contract and subordinate contract The master contract is a contract that exists independently of other contracts. A slave contract is a contract based on the existence of a master contract. The guarantee contract is a typical example from the contract. The invalidity and termination of the main contract will lead to

Invalidation and termination of the contract, and vice versa.

(5) Paid contracts and unpaid contracts are contracts in which one party must give the other party corresponding rights and interests in order to obtain its own interests. Free contract refers to a contract in which one party can obtain benefits from the other party without giving the other party corresponding rights and interests. Most of the contracts signed under the conditions of market economy are paid contracts.

(6) Major contracts Major contracts refer to contracts with certain forms and procedures required by law, and major contracts refer to contracts with certain forms and procedures not required by law.