This paper introduces the remote sensing mechanism and methods of water pollution and application on water pollution monitoring in Guangzhou Section of Pearl River. The research indicates that water reflectance in VI NIR bands becomes decreasing as the increase of water pollution. Through comparison

it can be found that classification and segmentation image of remote sensing may distinguish and recognize water pollution more effectively after logarithm

IHS and KL transformation. Time spatial distribution images of water pollution are made through the above techniques

and the time spatial distribution characteristics and changing trends are summarized through combination to ground analytical and investigation data of water quality. A regional early warning system of water pollution of whole drainage area is built up by use of GIS technology

processing of latest remote sensing data and the research of pollution sources. This research provides new information for the large scaled monitoring of water pollution and water resources protection.