How does the tax bureau verify the relationship between brother and sister: the public security organ of the local police station issues a certificate, and DNA determines it. According to the relevant information, it is the most authoritative to prove the relationship between brother and sister and the household registration. The certificate issued by the public security organ is also limited to the brothers and sisters whose household registration books are together. If the household registration books are not together, there is nothing the police station of the public security bureau can do. The police station only manages the household registration, and has no authority and business to issue the certificate of kinship. If the relatives are not in the same household registration, the public security organ will not grasp the kinship. Brothers and sisters whose household registration books are not together can collect the completed forms that can prove kinship by retrieving their personal files, academic records, work files and parents' files. Both brothers and sisters are here, and they can make DNA judgments to determine their blood relationship.