Legal analysis: The rental contract must be filed with the real estate department and stamped with the real estate bureau to be valid.

Legal basis: Article 734 of the "People's Liberation Army and Civil Code of the People's Republic of China" Upon expiration of the lease term, if the lessee continues to use the leased property and the lessor does not raise any objection, the original lease contract shall continue to be valid , but the lease period is irregular.

Article 32 of the "Contract Law of the People's Republic of China" Where the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign or seal it.