According to the statistic provided by United Nations Population Division, there are almost 200 million immigrants including 9.2 million refugees in the world. It counts for 3% world's population and is still increasing. In the process of globalization, it seems to be a natural phenomenon; yet stated by the Global Immigrant Condition Report published by Global Commission on International Migration, it is estimated that the total population of illegal immigrants are between 2.5 million and 4 million annually. In modern society, since human trafficking has gradually been defined as a type of slavery and the international awareness on fighting against transnational crimes, the human trafficking and smuggling has been regarded as an international crime and thereby generates new international rules.However, whether the conducts of human trafficking can be directly defined as international crimes without the enactment in domestic system to ensure their culpability has not yet reached consensus under international law among scholars. Furthermore, for avoiding disorder and possible obstacles when enforcing international law as well as promote international cooperation when dealing with transnational crime, how to claim criminal jurisdiction without violating international and intervening other States' sovereignty becomes the first task for each state to make and enforce relevant criminal laws. Therefore, based on two abovementioned perspectives, this article is aimed at reviewing the related issues of claiming jurisdiction for human trafficking conducts under international law.