The Customs Act provides for a general rule all goods entering Korea shall be subject to customs duties as set in the customs tariff schedules as other fees and taxes determined except those excluded by virtue of the Customs Act or intentional agreements. Importation begins from the time carrying vessel or aircraft enters Korea territorial jurisdiction with the intention to unload the same until the time the goods are released or withdrawn from the customhouse upon payment of the appropriate duties. Imported articles may be categorized into prohibited importations, dutiable importations and conditionally free importation. Some other articles are qualifiedly prohibited, meaning they can enter the country after compliance with certain conditions. If there is any conduct violating these act, criminal sanctions may be imposed for the prevention and suppression of smuggling and other frauds, and the enforcement of tariff and customs act. As a result importers who intentionally violates Korea Customs Act may be subject to criminal prosecution. Many major provisions of customs act have imposed severe sanctions for customs crimes in comparison with other crimes due to general rule of criminal law. There is a great deal of activity in Pusan area relating to smuggling of narcotics and prohibited drugs, obscene articles and weapons. On one side, criminals who seek to profit by narcotics or drug threaten public health and human environment, On other side, weapon smuggling is a significant threat to our national security. However the studies on customs crime and customs act have not been viewed. Thus this Article overviews especially the customs crime and criminal sanction focused on domestic customs act.