The lake Database of China is a data constitution of lake information, including various feature of lakes with an area lager than 10 km². In the database, all choice data are stored on the established format then inputted to micro-computer for further application. The lake data are not only characterized by a large number of data, but also by index keywords of lake's name and code, multiple and parallel lake classifications, lake dynamic change and spatial distribution. Logical structure of lake database is well knit. It is composed of China's lake distribution, lake graph and lake attribute, thematic data of some lakes and some analytic models. Computer program structure of lake database is composed of some layers, controlled by main program. First layer includes lake graph, attribute, eutrophication database of more than twenty lakes, and application modules. Lower layer can be operated by higher layer and can return to it. The operation of the lake database is not only simple hut convenient.