Dr. DIEP Sophal, a faculty member of Khmer Culture and history of the College of Social Sciences. He went to Russia in 1984 to study at the preparatory faculty of Voronezh State University. He recieved "Master of Art" from Voronezh State University in 1992. Morover, he earned his PhD degree in General History on "The Border of Cambodia". Recently, he has published the entittled "The Causes of the Cambodian war"