This study aims to analyze protocol & security systems of international conferences such as 2010 Seoul G20 Summit, 2012 Seoul Nuclear Security Summit and to propose Improvement strategies. The results derived from this study are as follows. First, it is necessary to support the establishment of international conference laws. We should select a major agency for 'International Conference Industry Promotion Act', coordinate of the system of international conference laws, resolve potential conflicts, maintain consistent on support organization of international conferences. Second, it is necessary to coordination among different ministries that control security relevant laws. We should solve clashes possibility between a few laws on security system which is closely related to protocol & security of international conference. Third, it is necessary to produce a joint protocol handbook of government for establishing protocol & security system of international conferences. We should try to confirm protocol & security system of international conferences through publishing a joint protocol handbook of government from their own protocol handbook of the executive, the legislature, etc. Forth, it is necessary to build and strengthen expertise of PCOs(professional convention organizers). We should find and assist several PCOs for achieving government policy that develop industrial foundation on international convention and train human resources on international convention expected next generation of promising industries.