legal ground
Article 686 of the Civil Code of People's Republic of China (PRC)
The guarantee methods include general guarantee and joint liability guarantee.
If the parties have not agreed on the way of guarantee or the agreement is unclear in the guarantee contract, they shall bear the guarantee liability according to the general guarantee.
Article six hundred and eighty-eight
If the parties agree in the guarantee contract that the guarantor and the debtor shall be jointly and severally liable for the debt, it is a joint liability guarantee.
When the debtor of joint and several liability guarantee fails to perform the due debt or the circumstances agreed by the parties occur, the creditor may require the debtor to perform the debt, or may require the guarantor to assume the guarantee liability within the scope of its guarantee.