Legal analysis: Only signed contracts are valid. If the parties conclude a contract in the form of a contract, the contract is established when both parties sign or seal it, and the signature or seal is valid. If the parties press their fingerprints on the contract, the people's court shall determine that it has the same legal effect as the signature or seal. If the parties fail to adopt a written form, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.

Legal basis: Article 490 of the Civil Code of People's Republic of China (PRC). If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. 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.