It is a basic and independent obligation for the civil servant that obeying to the country, the law and order of constitution with loyalty. On the basis of freedom and democracy in a law and order country, the authority should prevent the destroyer from governing fate of a country as well as check the character and loyalty of the civil servant necessarily.Fundamentally, the civil servant will be interfered and aggrieved the essential right when the commission is checked by the government authority. It would be written remarks giving some analyzing and discussing on the relation of protecting the privacy and checking the character and loyalty of the civil servant, the regulation and examining about national security and grand interest by checking the character and loyalty of the civil servant, and examining the regulation about the characteristic and loyal obligation of the civil servant, etc for discerning balanced statement between protecting the essential right of constitution and national security & grand interest. At the meantime, it will criticize and advance the amendment to "the draft of checking the civil servant related to national security and grand interest act". We hope to achieve the balanced statement assured between protecting the right of privacy & free communicate of the civil servant and national security & grand interest.Keywords: National security, Grand interest, Character and loyalty, Obligation of loyalty, Check