No marriage may be contracted if the man and the woman are lineal relatives by blood, or collateral relatives by blood up to the third degree of kinship.

• 直系血亲是指与自己有直接血缘关系的亲属，即生育自己和自己所生育的上下各代的亲属，如父母、子女、祖父母、孙子女、外祖父母、外孙子女等。