The legal person is the legal representative, and the private seal of the legal representative can replace the signature in legal effect, but it is more convenient to determine the authenticity of the signature in the case of dispute, and the signature is more widely used. At the same time, the signature of the contract becomes effective, and the legal person's private seal cannot replace the signature.

legal ground

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.