The most important expectaion from defense equipment and weapons acquisition system (DAS) is to fulfill current and future needs of Armed forces in a variable and complex environment effectively and timely. For this purpose, it is necessary that the DAS be able to perform some key activities and this requires some basic capabilities. The capalities enable the DAS to change and rearrange its routine processes and available resources according to environment changes. By interviewing 14 defense acquisition experts, this research tries to identify the capabilities. Through Theme analysis of interviews and Content analysis of 6 available formal defense documents, 12 capabilities were identified. Using the Interpretive Structural Modeling (ISM) showed us 10 capabilities: intelligent management of information and knowledge; looking forward and environment changes perception; creation of common concepts and language; technological perception and management; leading of domestic and foreign capacities; development of robust policies and flexible strategies; innovation and creativeness; management of acquisition program; decision-making; and cooperation between actors located in influence area.