Sponges are marine organisms that have associations with microorganisms. The association fungi in sponges have a chemical and ecological relationship. These bioactive compounds have potential in the pharmaceutical field. This research aimed to explore bioactive compounds of association fungi in sponges that live in coral, seaweed and mangrove ecosystems. The research consisted of isolation, purification, extraction, antibacterial testing, molecular identification, antioxidant testing and toxicity testing. The research was conducted on March to September 2020 in Karimunjawa Island. The results showed that the sponge association fungi isolates had antibacterial activity against the Multi Drug Resistant (MDR) pathogens Staphylococcus aureus (Sa), Escherichia coli (Ec), and Staphylococcus epidermidis (Se), Pseudomonas aeruginosa (Pa) and the fungi Candida albicans (Ca). The identification results of the active association fungi were Circinelloides sp., Xylariaceae sp., Trichoderma asperellum, Aspergillus sp. and Pleosporales sp. . The extracts of these fungi had antioxidant activity with an IC50 value of 1071,62; 643,35; 1020,32; 805,70 and 784,31 mg/L. Furthermore, they also had an LC50 value of 462,67; 355,47; 504,92; 482,15 and 435,88 mg/L. Keywords: Antimicrobial, Antioxidant, Fungi, Sponge, Symbiosis