According to the provisions of the United Nations Convention on Contracts for the International Sale of Goods, ownership guarantee has three meanings:

1. The seller should guarantee to the buyer that he does have the right to sell the goods. If the seller sells the stolen goods to the buyer, it will violate his obligation to guarantee the ownership of the goods;

2. The seller should guarantee that there are no rights of others on the goods that are not known to the buyer when the contract is made. Such as mortgage rights, liens, etc.;

3. The seller shall guarantee to the buyer that no third party will make legal claims on the goods submitted by it for infringement or other similar reasons. For example, the goods sold by the seller and their use must not infringe the patent rights, trademark rights, etc. of third parties. Ownership guarantee means that the seller guarantees that it has full ownership of the goods it sells, and it must be goods over which a third party cannot assert any rights or claims, such as the absence of any security rights that have not been disclosed to the buyer. The types of ownership guarantees include: sale-type guarantee, transfer-type guarantee, and ownership retention.