Legal analysis: When writing an IOU, you should generally pay attention to 1. The subject of the contract should have civil capacity and rights 2. Clearly state the subject matter, quantity, and quality of the contract 3. The contract should stipulate the liability for breach of contract and the resolution of disputes method.

Legal basis: "The People's Republic of China and the Civil Code" Article 470 The content of the contract is agreed upon by the parties and generally includes the following clauses:

(1) The parties' Name or title and address;

(2) Subject matter;

(3) Quantity;

(4) Quality;

( 5) Price or remuneration;

(6) Time limit, place and method of performance;

(7) Liability for breach of contract;

(8) Methods to resolve disputes .

The parties may conclude a contract by referring to the model texts of various types of contracts.