Carbapenem-resistant Acinetobacter baumannii (CRAB) is a gram-negative bacillus that commonly causes nosocomial infection found in Indonesia. CRAB infection caused by Acinetobacter baumannii that is resistant to Carbapenem. Resistance occurred because bacteria that cause infections easily treated with antibiotics become difficult to treat due to the uncontrolled use of antibiotics. A. baumannii has been resistant against the carbapenem class of antibiotics; and therefore, antibiotics are required to be obtained from natural ingredients with optimal working power, such as from the marine sponges of Axinella sp. The purpose of this study was to determine the antibacterial activities of bacteria associated with marine sponges of Axinella sp. against CRAB. Bacteria associated with Axinella sp. were isolated by differential dilution and cultures on Zobell 2216E media. An antibacterial activity test was performed using the overlay method. The antibacterial activity test was carried out to determine the presence of inhibition zones. The test results showed the bacteria associated with a marine sponge of Axinella sp strain 3 KD had antibacterial activity against CRAB growth with the formation of an inhibition zone of 16 mm. The results of the catalase test and oxidase test depicted that the isolates belong to the family of Staphylococcaceae. Isolates bacteria associated with a marine sponge of Axinella sp. were potential antibacterial agents against CRAB growth.