The new system means children will no longer be obliged to go by their biological father's surname and can follow that of their mother or even step-parent, reported Joongang Ilbo yesterday.

The move is a break from the patrilineal tradition of Confucianism that had been observed by Koreans for centuries.

South Korea's Supreme Court announced on Sunday that the new family registry system will take effect in January next year.

The current so-called hoju system, where records of offspring are subsumed under that of their biological father or, in the case of married women, that of their husband, will be scrapped.

South Korea's Constitutional Court ruled in 2005 that the hoju system is a violation of gender equality and other constitutional rights of the people.

Under the new system, a child can use either the mother or father's surname, and even change their own surname when their parents divorce or remarry, the Supreme Court said.

But siblings have to use the same surname, according to the new rule.

Also, an adopted child or stepchild can take the surname of his new parent if proper applications are done through the court.

That would mean stepchildren will have the same legal rights as the step-parent's biological children, as he could follow the family name of the legal father and is registered as such, reported the Korea Herald.

Under the hoju system, adopted children and stepchildren have no rights to inheritance.

The Korea Herald, however, remarked yesterday that the new system would perplex many South Koreans as it challenges the country's concept of a family.

Under the age-old hoju system, the status of each family member is defined in terms of his or her relationship to the biological father.

When a husband dies, he is usually succeeded by his first son, not by his wife.

However, under the new system, particulars of every family member will be registered in his or her own individual record book.

Right-wingers led by Confucian scholars are up in arms against the abolishment of the hoju system, the Korea Herald reported.

Confucianist scholars have argued that the system has helped keep traditional family values and hence preserve national unity, said the paper.

Scrapping the system would throw society into disorder, they warned.