Abstract
The followings are required to establish uniform principle of criminal jurisdiction for international cyber crime into customary international law; (1) clear guideline of UN for promoting national practice (2) formation of general practices based on these guidelines (3) these general practices should obtain legal confidence. International society is in close cooperation for investigating and controlling cyber threat. The US FBI has closed down the largest online crime space called 'Darkcode' and prosecuted related hackers based on joint investigation with 19 countries including England, Australia, Canada, Bosnia, Croatia, Israel, and Rumania. More and more people in Korea are raising their voices for joining cyber crime treaty, 'Budapest Treaty.' Budapest Treaty is the first international treaty prosecuting cyber crime by setting out detailed regulations on internet criminal act. Member countries have installed hotline for cyber crime and they act together. Except European countries, America, Canada, and Japan have joined the treaty. In case of Korea, from few years before, it is reviewing joining with Ministry of Foreign affairs, Ministry of Justice and the National Police but haven't made any conclusion. Different from offline crime, cyber crime is planned in advance and happens regardless of border. Therefore, international cooperation based on position of punishing criminals and international standards. Joining of Budapest international cyber crime treaty shall be done as soon as possible for enhancing national competence.