In this study, we developed the EcoProDB database, which contains information on Escherichia coli proteins identified on 2-D gels along with other resources collected from various databases and published literature. The database comprehensively covers the expression levels of E. coli proteins under different genetic and environmental conditions. In addition, the database has detailed information on subcelluar localization, theoretical 2-D map and experimental 2-D map. Users can easily access these sources, and compare them with their own 2-D gels via an interactive web interface and application, such as the Map Browser and the Online tools. Using EcoProDB, users can efficiently grasp the core information associated with the proteins and 2-D gel results obtained from several different experimental sets for more convenient and enhanced analysis.