Ever since the formation of the International Criminal Court on July 1, 2002 in Hague pursuant to the Rome Statute, international criminal law has graduately been under the spotlight of the international community. Numerous countries amend their domestic penal laws in order to effectively prosecute and punish international crimes such as the crime of genocide, crimes against humanity, war crimes and the crime of aggression. This Article will first review and discuss the elements and the enforcement mechanisms of international crimes, and then identify and examine in great detail the loopholes of the punishment of international crime violations under Taiwan's current Criminal Code. Finally, a preliminary reform proposal will be furnished.