The system of theoretical Geography is divided into 3 series in this paper. The first series is Theoretical Geography in its strict meaning, which indicates general geographical laws; the second series is Werder-meaning Theoretical Geography, which contains strict-meaning Theoretical geography and the theories of physical geography and Human geography; and the third series is Generad Theoretical Geography, which ihvolves applied theories of various, geographic things, besides theoretical geography in wider semse.The theoretical geography contains 3 branches. Regoinal Science, Geographical Environment Science and Geo-system Science. some basic concepts of these branches have been discussed in this paper.