legal ground
Article 395 of the Civil Code
The following properties that the debtor or a third party has the right to dispose of may be mortgaged:
(a) buildings and other land attachments;
(2) The right to use construction land;
(3) the right to use the sea area;
(4) Production equipment, raw materials, semi-finished products and products;
(5) Buildings, ships and aircraft under construction;
(6) means of transportation;
(seven) other property not prohibited by laws and administrative regulations.
The mortgagor may mortgage the property listed in the preceding paragraph together.
Article 397
Where a building is mortgaged, the right to use the construction land occupied by the building shall be mortgaged together. Where the right to use construction land is mortgaged, the buildings on the land shall be mortgaged together.
If the mortgagor fails to jointly mortgage in accordance with the provisions of the preceding paragraph, the mortgaged property shall be regarded as joint mortgage.
Article 402
Where the property specified in Items 1 to 3 of the first paragraph of Article 395 of this Law or the building under construction specified in Item 5 is mortgaged, the mortgage registration shall be handled. The mortgage is established at the time of registration.