Abstract: For the past thirty years, the stratigraphy Of Gansu Province has been studied using the classical theory of stratigraphy. "A Guide to the Stratigraphy of China and Explanatory Notes on the Guide to the Stratigraphy of China"（called the"Guide"hereinafter）promulgated by the National Commission on Stratigraphy in 1980 has ushered in a new stage of the study of China’s stratigraphy, i.e. the stage of modern stratigraphy. Although The "Guide" has been promulgated for many years. people have not come to a correct understanding and knowledge of the theory of multiple stratigraphie classification as an important componet part of the theory of modern stratigraphy in the current field work. There are many divergent views about it and sometimes even either this or that view is considered to becorrect. Whether the understanding of the theory of stratigraphy is correct or not has a direct bearing on the research level of stratigraphy, guaiity of geologicsl mapping and results of other geological work. According to the status guo of the study of the stratigraphy of Gansu Province, this paper elucidates a few important concepts and principles for. the theory of multiple stratigraphic classification with deliberate purpose and selectively, points out four main problems in the study of the stratigraphy of Gansu Province and discusses the future direction and way in stratigraphic study.