legal ground
Article 400th of the Civil Code of People's Republic of China (PRC).
To establish a mortgage, the parties shall conclude a mortgage contract in writing.
A mortgage contract generally includes the following clauses:
(1) The type and amount of secured creditor's rights;
(2) The time limit for the debtor to perform the debt;
(3) The name and quantity of the mortgaged property;
(4) the scope of the guarantee.
Article 40 1
The mortgagee and the mortgagor agreed that if the debtor fails to perform the due debt before the maturity of the debt, if the collateral belongs to the creditor, it can only be paid in priority according to law.