The massive influx of migrant workers has started 1980s in Korea due to the rapid wage increase and the evasion on arduous job. According to the survey of Ministry of Justice in 2010, the number of stay foreigner who live in Korea has been over 1.20 millions, the half of whom are the migrant worker, which shows that they are one of the main members in our society. The constitutional rights of Korea grants foreigner. Of course, the rights should be equally accepted to the migrant workers. However, the structure of the employment permit system seems to permit only limited rights to documented migrant workers. This study focuses on pointing out for undocumented migrant workers`` human rights. The current domestic legal system and International Human Rights which are related directly and indirectly with the documented and undocumented migrant worker was analyzed and examined. First, it is natural that the International Covenant on Human Rights guarantees human Rights and fundamental rights of the migrant worker at the same level of the national workers. Particularly, on December 18, 1990, the United Nations has adopted ``International Convention of the Protection of the Rights of All Migrant Workers and Members of the Their Families``. Therefore a legal basis for protecting migrant worker - contained undocumented migrant worker- in international level has been existed. On the basic of it, the improvement with the legal task to protect the human right of undocumented migrant workers`` were presented.