Legal basis: Article 682 of the Civil Code of People's Republic of China (PRC) guarantees that the contract is a subsidiary contract of the principal creditor's rights and debts contract. If the principal creditor's rights and debts contract is invalid, the guarantee contract is invalid, unless otherwise stipulated by law. If the debtor, guarantor and creditor are at fault after the guaranty contract is confirmed to be invalid, they shall bear corresponding civil liabilities according to their faults.