Soft corals are invertebrates living on coral reefs that produce bioactive compound that can be used such as an antibacterial, antifungal, anti-tumor,and anti inflamantory that are beneficial for the pharmaceutical industry. Several studies have shown that fungi are very rich of natural chemical compounds that are potential as a source of new drugs, but there is few research in marine fungal symbionts. In this research we collecteda soft coral Sinularia sp. as source of marine fungal symbionts from Panjang island of the North Java Sea.A total of15 fungi were successfully isolated and screened usingoverlay method against pathogenic fungi Candida Albicans and Aspergillus flavus. The results revealed that a fungalsymbiont was able to inhibit the growth of pathogenic fungi. Phytochemical tests showed that phenolic, triterpenoid and flavanoid compounds were detected within fungal extract. Molecular identification based on 18s rRNA gene showed that the active fungal was closely related to Aspergillus unguis.