Abstract
A development of the Siem Reap basin has been recently planned in Cambodia. In addition, tropical lowland is a fragile area where global climatic change has a great effect on its physical environment. The purpose of the present study is to evaluate the flowing and physicochemical properties of Siem Reap River as affected by human activity. It is important to make clear the hydrological characteristics and their factor in Siem Reap River as a basic study in order to advance the environmental preservation in the Angkor monument area.