This study is to propose the improvement of security related regulations to reinforce security activity and actualize constitutionalism in the National Assembly. For the purpose, some improvements could be considered as followings; First, legislating of regulations including some articles on the scope of security activity such as order preservation at assembly hall, facility security, security agents\' right and protection of personal is necessary. Second, changing the organization and command system of security management is necessary for the unification of security activity and efficiency of the job. Also clear definition of terminology on the security job is need. For the shake of above object, one officer in charge of situation management and three section such as the personal protection section, facility security section and order preservation section could be substructured under security department. Third, elimination of unnecessary article on the arrest of red handed criminal in the assembly hall and on the physical checkup of audience by security agent is need. Also legislating of regulations on the hoarding of person who could disorder is necessary. Forth, legislating of regulations on the cooperation with government branch, judicial police power, carry and use of weapon and uniform and equipment to reinforce practical efficiency of security activity. For the proper legislating of the regulations, comparition with other public organizations such as presidential security Service, police, private security could be considered.