1. The testator must have testamentary capacity;
2. The content of the will must be the expression of the testator's true intention;
3. The estate disposed by will can only be the property legally owned by individuals, and the disposal of other property is invalid;
4. The will shall not cancel the right of inheritance of heirs who lack the ability to work and have no source of income;
5. The inheritance share of the fetus should be retained in the will;
