Since modern ages, the relationship of the privilege and obligation between the nation and the public official have been founded step by step. Moreover, after the Protection Law has come into force, the public official's leagal system has been gradually well-made. The axis of the study is based on the public official's concept, and comparing the modern leagal system. They are including the public official's concept, catagories, characteristics of therelationship, examinations and employment, privilege and obligation, responsibilities and questions relating. Therefore, the purpose of the study is for researchers having a deeper understanding in the public official's leagal system.