Seals cannot be used in place of signatures in self-written wills.
"Succession Law of the People's Republic of China"
Article 17 Notarization of a will shall be handled by the testator through a notary authority.
A self-written will is written and signed by the testator, and the year, month and day are indicated.
A written will must be witnessed by two or more witnesses, and one of them should write on behalf of the will, indicating the year, month, and day, and signed by the attorney, other witnesses, and the testator.
A will made in the form of a recording must be witnessed by two or more witnesses.
In critical circumstances, a testator may make an oral will. An oral will must be witnessed by two or more witnesses. After the critical situation is resolved, if the testator is able to make a will in written or recorded form, the oral will will be invalid.