This study investigated the dimensional plan of Kor Sork temple in Preah Pithu complex, Angkor by civil surveying, 3D scan, measured integer ratio and regularity. According to epitaph and preceding researches, Khmer temples were built based on structural planing with the constant ratio and regularity by using special construct measure scales "Hasta" and “Byama”. The study assumed the same unit method was applied in Kor Sork temple and identified the regularity of actual measurement value about the temple. The assumed construct measure scale (Hasta) used for the design of this temple is 413mm. The overall apart arrangement of the temple is different in the East-West direction and the North-South direction. In the East-West direction, the whole scale is 180 hasta, and it is divided into 20 hastas. On the other hands, it was confirmed that the North-South direction is 96 hasta and it was divided four quadrants in 24 hastas. Regarding the detailed design, the regularity according to the constant ratio was confirmed. 7 hasta was used as the basic unit on the first floor and 6 hasta were used as the basic unit on the second floor of the terrace. the basement and the central sanctuary is of 6 hasta and 8 hasta were used as the basic standard.

We surveyed Preah Pithu monument group site in Angkor. We made the map of present condition throughout the actual measurement and 3D scan. And we restored the floor plan, and completed the map of site placement. During this processing, we confirmed the middle axis of temples and studied the relation of temples and made clear the order of sites. Throughout this studying, we verified the middle axis of sites is not matched in Preah Pithu monument group. It is different aspect comparing with general Khmer religion architectures which were built with the planification belonging to strong royal authority and shared main axis through whole sites. In other words, we can estimate that Preah Pithu monument group was not built with planification rather than expanded as occasional demand during the process of actual use

The international community has been collaborated for the preservation of Angkor site in the last twenty years. This case which is the heritage conservation through cooperation is an exemplary instance for developing countries and warring nations. For this study, we analyze each of declarations that is adopted through three intergovernmental conferences for the preservation of Angkor and study how the policies of the conservation work. Tokyo Declaration at 1993 is included a pledge of the cooperation from all the countries of the world and an emergency measure and an advice of the policy for conservation on Angkor. Paris Declaration at 2003 is mentioned that the emergency measure for last ten years is effective for conservation of Angkor and emphasized the necessity of practical use of heritage like sustainable development and ethical sightseeing. Angkor Declaration at 2013 assures exertions of last 20 years and convinces that all of activities about Angkor is a commendable precedent to another World Heritages in danger. And it is mentioned a practical use of heritage which is more crucial and new conservation of Angkor.