Sofware muintainers use a variery of techniques and representations for undersranding programs. Most of thess representations first focus on the control structure of a program such as call graphs, control flow graphs and paths. We propose a new approach for program understanding that is data-centered-it first /muses on data and data relationships. We have experimented on both small and large Cobol programs from industry IO determine i f our methods are useful for program understanding and sojiware maintenance. We have developed a Data-centered Program Understanding Tool Environment called DPUTE that is currently being evaluated and enhanced by our i&rrial partners.