An introduction into the foundations of constructing a marketing data base is presented for the systems and marketing executives who are familiar with basic computer technology methods. The techniques and concepts presented are now being implemented by major organizations in the development of Management Information Systems (MIS). A marketing data base in this presentation is considered to be a logical or conceptual data base which does not exist as a physical entity in one segment of the corporate MIS, but, rather, exists as a logical set of data that can be located by a software "definition table." Other data bases can utilize any appropriate elements from the corporate MIS. A definition table defines each data base within the MIS. The concept developed here relies upon the ability to utilize one common data base as several data bases through the process of software manipulation, this serves as the corporate MIS and is updated in a unified manner. The advantages are seen in terms of file maintenance, time and storage requirements. (NH)