The problem of endocrine disrupting chemicals in river water came to be focused on in recent years, and there were several field measurements of water itself. But the information about the chemicals storing in the sediment which constitutes a river channel has not investigated. The objective of this research is to understand where and how the endocrine disrupting chemicals are stored on and under the ground surface of river channel. The scenario about the chemicals storing was discussed on the basis of the result of numerical experiment by Sekine et al (2005). Field investigation in Tama-river was conducted to verify the validity of this scenario.