This paper presents an effective framework of site selection for identifying and locating potential pollution sites within a river basin. Spatial data mining was used to delimit three classifications of pollution potential areas from information of industrial types, industrial distribution, historical pollution events, illegal dumping sites, reports and interviews of local residents. The Geographical Information System (GIS) was used to create maps of pollution potential areas by overlaying the available historical background data. Suspected spots were then located through aerial-photo interpretation of the pollution potential areas. Finally, field checks with the Global Positioning System (GPS) were carried out to inspect the suspected spots located by aerial-photo interpretation, and the candidate sites were then chosen for soil sampling. Results were obtained from field soil sampling surveys of 41 selected sites, which were analyzed by a laboratory method. Among the 41 selected sites, there were found eleven soil polluted sites (26.8%), two groundwater polluted sites (4.9%) by heavy metal, and twenty-two dumping sites (53.6%) [Seven of them are hazardous industrial waste sites (17%) and fifteen are general waste (33.6%)]. This shows that the systematical procedure of site selection is considerably reliable.