Preah Vihear Temple is an old Khmer temple ruins situated on the border of Thailand and Cambodia. UNESCO decided to list it as a World Heritage Site on July 7, 2008. However, the two countries have been in a states of border conflict for about three years. Therefore, the International Court of Justice ruled that both Thailand and Cambodia should pull their troops out from the site of Preah Vihear temple and establish a demilitarized zone around its ruins in order to facilitate negotiations to finally end the long-standing spat between the two countries on July 18, 2011. This paper attempts to show the role of International Court of Justice in border conflict between two countries. It also looks for the difference whether the conflict lead to the combat or not, according to the political position of Thai's Prime Minister.