The threat of terrorism is internationally appreciated as one of the most serious security issues, along with the supernational / non - military threat of expanding Weapons of Mass Destruction, while decrease in the possibility of general war between nations is the current trend in World security environment. Terrorism including the ‘9․11 crisis’ and a series of terrorism activities occurred in many nations can happen anytime and anywhere, and it evidently shows that the method, plan and the target region are straying out of the framework of traditional terrorism. Moreover, advance in technology enables diversified methods of terrorism. The new types of terrorism, including cyber terrorism, financial terrorism and biochemical terrorism, are already well spread out, and the contents and extensions are continuously changed and enlarged. Accordingly, the international society has formed the consensus of mutual response including regulation and penalty in pan-World level against the threat of terrorism and force exercise, and the international cooperation is gradually enhancing. However, the threat and danger they carry towards nations/society and citizens are getting more serious exponentially, while the legislative capacity(including penalty) could not follow the rate. Reflecting the trend, there has been an increased interest and activity inside our nation as well to respond to terrorism. Most noticeable way is enacting ‘Terrorism Prevention Law’ as a general law in several options being discussed, but in order to respond in criminal law-level such as enacting ‘Terrorism Prevention Law’, different conditions exclusive to terrorism should be able to be extracted, and therefore a separate discipline from other criminal legislations is required. Regarding the necessity of integrated ‘Terrorism Prevention Law’, a research in depth on whether ROK is in the target range of serious terrorism act, and whether improving currently existing criminal law sections would be a better method, is required. The general opinions put more weight on the side of establishing integrated ‘Terrorism Prevention Law’, since although ROK is not the direct target from the Middle-East terrorists, it is participating in counter-terrorism activity such as dispatching forces to Iraq and Lebanon, the terrorists are expanding their range of field of action, their main targets are diplomatic offices and consulates, the existence of USFK, and the administrative factor of ‘National Counter-terrorism activity guidance’ which is the Presidential directive Number 47. In my opinion, when considering the current trend inside and outside the country, it is necessary to establish the ‘Terrorism Prevention Law’, and the way to do that should be complementing contents not dealt with in existing legislations, or adding terrorism-specific contents and procedures on the bill. For detailed contents, establishment of the concept of terrorism, military support in necessity, enhancement of punishments against activitis including the offense of organizing terrorist group, planning / plotting / attempted terrorism, eased communication limitation measures compared to general crime, and legal force factor towards individuals and objects, need to be reflected. After all, the ‘Terrorism Prevention Law’ should be established under the obligation of preserving the freedom and natural rights of citizens, while directing national agencies organically and generally for accurate information and analysis about terrorist groups, for national security, the order and general welfare of citizens.