Legal analysis: valid, the contract requires a guarantor, but the guarantor has not signed it. Of course, the contract is valid, but the guarantee contract is invalid. Because the contract is the master contract and the guarantee contract is the slave contract, whether the guarantee contract as the slave contract exists or not will not affect the legal effect of the master contract. The loan guarantor establishes a guarantee contract relationship with the lender. If the guarantor does not sign the guarantee contract or the guarantor in the loan contract, the guarantor and the lender will not establish the guarantee contract contact, and there will be no guarantee responsibility.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 387 Where a creditor needs security in order to ensure the realization of his creditor's rights in civil activities such as lending, buying and selling, he may establish a security interest in accordance with the provisions of this Law and other laws. If a third party provides a guarantee for the debtor to the creditor, it may require the debtor to provide a counter-guarantee. The provisions of this law and other laws shall apply to counter-guarantee.

Article 391 Where a third party provides a guarantee and the creditor allows the debtor to assign all or part of the debt without its written consent, the guarantor shall no longer bear the corresponding guarantee liability.