The petroleum geological data as a significant basis for researchers are a difficult point in data management. This paper details the software GeoStudy, used for petroleum geological comprehensive study, in its major functions of data management modules. The GeoStudy can mange data both for itself and for specialist's needs, holds dual management functions in exploration database and archives in oilfields or institutes. This software is designed for the actual needs of petroleum geological data and is a key to the difficulties in data management which have been puzzling the researchers.