Legal analysis: A contract signed by a legal person is valid without an official seal, and a contract signed by the legal representative of the company within the scope of business and authority of the company is valid even without an official seal, unless otherwise agreed by the parties. The legal representative of the company shall be the chairman, executive director or manager in accordance with the articles of association, and shall be registered according to law.

Legal basis: Article 13 of the Company Law of People's Republic of China (PRC), the legal representative of the company shall be the chairman, executive director or manager as stipulated in the articles of association, and shall be registered according to law. Where the legal representative of the company changes, it shall go through the registration of change.

Article 490 of the Civil Code of People's Republic of China (PRC): If the parties conclude a contract in the form of a contract, the contract is concluded when the parties sign, seal or fingerprint it. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it. A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.