This study is based on organizational information processing theory（OIPY）. Differed from the former research that focused on the organizational level, this research goes deep into subunit level. It introduces the intermediate benefits, and brings forward a theoretical model on the perspective of subunits in order to discover how differentiation among subunits affects overall information system benefits. It collects data from 22 manufacturing enterprises in China in the form of questionnaires, and analyzes them with the methods of structural equation models. The results tell us why the information system benefits are different in various enterprises, and provide a theoretical basis to improve organizational performance through maximizing the function of information system