The main purpose of this article is to analyze on the South Korean Civilian Massacre by the North Korean Army and the left wings during the North Korean Occupation of South Korea. This paper is aimed to put a valuation on the problematic issues in War Crimes Division in Korea(KWC). This study was the reference of conducted with following documents: NARA, RG 153 Records of the Office of the Judge Advocate General Army, International Affairs Division; War Crimes Branch; “Investigation of Atrocities against POW’s in Korea”, 1952-1954, Entry A1 181, Box 891-976, KWC #1∼#1848; “Interim Historical Report”, 30 June 1953; “Final Historical and Operational Report”, 31. May 1954. Since the outbreak of the Massacre, the existing studies regarding this issue concentrated on elucidating actual conditions of civilian massacre and studies in the region have been still focused on understanding each regional cases, expected size, and so on. However, it has been challenged to understand entire matters of victims and wrongdoers because the signed confession research throughout the area sampled some regions. Therefore, this study suggest a debate on the three problematic issues in those historical records. I found that those historical records oncy emphasize the perspectives of the anti-communism in while analyzing the massacres. Also they have been recorded without the sufficient and reliable resources. They have only been discussed about the mass slaughter committed by several specific forces which are included with the North Korean government, the police of the North Korean government, and the South Korean communists. We have to recognize other mass slaughters happened in the same region from July 1950 to January 1951. Especially, the mass slaughter of civilians, the murders of people who acted in a way to Anti North Korea happened in the same areas. Thus, I believe that we have to give a definition of other massacres. Most historical records do not demonstrate the reason many people should have been victimized in the massacres. For example, even though they put many pages to describe the massacre, there are few reliable resources in them. As a result of the poor research achievements on the historical records, it is very hard for us to identify what kinds of “military command chains” the massacres had been carried out. Thus, it is still ambiguous to what extent North Korean government involved in those tragedies. I think that the massacres happened during Korean War should be researched from the multidimensional viewpoints by closely relating to political, economical, and social issues. These approaches help us bring objectivity into my research. I also think that if we can make any research with more possible reliability and objectivity, that research would allow us to find the person who were responsible for those mass slaughters, and the reason they happened in the time. This work will help add further studies based on empirical researches that have been conducted until now and define that the massacre occurred independently or the government intervened in the massacre.