The current research aims to study the impact of each of the quality of accounting information system and organizational culture on the users' perceived usefulness, and to study the interactive impact of the organizational culture and the accounting information system quality on the users' perceived usefulness. Primary data were collected using a questionnaire developed using previous studies, and distributed to a non- probability sample of users of accounting information systems in the maritime shipping companies in Syria . 53 acceptable responses were received.Data have been analyzed using linear regression. The results showed that there is a direct significant relationship between the quality of accounting information system and the users' perceived usefulness. They also showed that the dimensions of organizational culture (human resources orientation and cooperation) affect the perceived usefulness directly. The results demonstrated that The interaction between the system quality and each of the human resources orientation dimension and cooperation dimension has an impact on the perceived usefulness of the accounting information system.