Legal analysis: When a citizen carries out a civil legal act in his own name, it is effective to use the personal seal, and the personal seal of the legal representative of the enterprise can also replace the signature, but when signing a contract, the signature of both parties is more secure.

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 stipulated by laws, administrative regulations or agreed by the parties shall be concluded in writing. 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.