Vietnam used to invade Cambodia is commonly known among modern Vietnamese people in the South. In our team, even those from the North and Central of Vietnam have rarely heard about the genocide of Pol Pot regime. In this project, we wish to reevaluate the intervention of Vietnam into the genocide of the Red Khmer Rouge regime back in Vietnam-Cambodia War 1979 in order to understand the postulated causes leading to two opposite viewpoints of both the Vietnamese and Cambodian government and citizens.