Unit 731 was a Japanese military unit for a covert biological and chemical warfare research and development, based at the Pingfang district of Harbin during World War Two. At the time, Japan which had small territories and lack of military strength considered a germ warfare as important. For the germ warfare, they had an interest in the structure of physiological human’s body. They did biological and chemical experiments on living humans from china or other countries. Unit 731 committed the large scale of the biological and chemical experiments from August in 1933 to July in1939. They called the human subjects ‘ Maruta’, which is ‘log’ in Japanese . The subjects were inhumanly experimented and dissected when they were still alive without any anesthetic for the accurate results. For five years, at least 3000 Marutas were sacrificed, mostly from China, some from Korea, Russia, and Mongolia. Also, there were a few of American and European prisoners of war from the Allied Forces.