Abstract: With the social economic development, gas stations are densely distributed in large cities. Most of gas stations are faced with accidental leaks and spills of the stored products (e.g., gasoline and/or diesel fuel). The leaks and spills have potential risk of pollution to the surrounding environment including soil and groundwater. In the last 30years, the investigation and remediation of the pollution from gas stations has become commonplace in many developed countries such as USA, UK and Japan. However, China initiated this work recently. In order to understand and characterize the pollution potential of gas stations in a typical shallow water-table area, 119gas stations located, and on Chongming Island and Changxing Island of Shanghai, in the upstream region of the Huangpu River, were investigated. The Analytic Hierarchy Process (AHP) method was applied to evaluate the overall leaking potential and to determine the leaking potential value of all selected gas stations. Four leaking potential levels for these gas stations were categoried by quartation method:9stations with extremely-high pollution potential (7.6%), 49stations with high pollution potential (41.2%), 47stations with fair pollution potential (39.5%), and 14stations with low pollution potential (11.7%). To verify actual leakage pollution levels, field monitoring was carried out at two out-of-business gas stations on Chongming Island which were determined to have high pollution potential. The field monitoring results indicated that heavy soil and groundwater pollution existed around the underground storage tank pit, piping area, and fuel dispenser area of these two gas stations. The primary soil contaminants included BTEX (benzene, toluene ethylbenzene, and xylene), naphthalene, and total petrol hydrocarbons (TPH), which were found at detection rates of 71.4%-88.9%. The detection rates for methyl tert-butyl ether (MTBE) and TPH in the groundwater were 33.3%-71.4% and 80.0%-100.0%, respectively.