Abstract: Analyses of the seepage water quality in the filter well constructed by Baisha waterworks in Jiangjin, Chongqing reveal that, through infiltration of sandy gravel in the river bed, the micro- polluted, high turbid river water can be converted into seepage water with suspended substances and bacteria well removed and turbidity visibly reduced. The contents of NO-3, COD, BOD and TOC in the seepage water are obviously reduced, and the removal ratio is over 75%. The change of major components in content is remarkable, while the micro-components have not clear change in content. The quality of the seepage water accords with the national standard for drinking water quality, and can be used as domestic water directly.