From the past until nowadays genocide is one of the fundamental crimes of humanity that cause to damage target groups like ethnic cleansing. Although Genocide and Ethnic Cleansing have commons there are separation points that exist. Also, both concepts can create similar development processes and consequences but under international criminal law, ethnic cleansing does not define as a crime, which creates huge problems with trials of ethnic cleansing and separation between genocide. Because of that “Elimination” purpose can be similar but ethnic cleansing more focus on specific areas and ethnic groups. This research will investigate historical developments of genocide and ethnic cleansing and find out common and separation points to create a general review of historical events and legal precedents.