Is the seal of the property contract valid without signature?

Legal analysis: effective. If the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign or seal it. As long as both parties sign or seal on one of them, the contract will take effect and be legally binding on both parties.

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.