Sponges are the most primitive of the multicellular, These organisms don’t have any mechanical defense system, so their early appearance in evolution has given them alot of time for the development of advanced secondary metabolites as chemical defense system. Sponges have the potential to provide drugs from chemical components against diseases. In this investigation the sponge samples, which it is Dysidea spp. , were collected at depth of 15- 20 meter, from locations on the coastline of Island Hengam in Persian Gulf of Iran. For identifying natural components, methanolic and diethyletter were used as extraction solvents, after removal of the solvents, the GC/MS spectra of the fraction were obtained. Then in vitro cytotoxic, antimicrobial, antifungal and antiviral activities were identified. In vitro cytotoxity screening, by XTT assay, against KB/ C152 and HUT-78/ C185 cell line, was conducted in this study in 1 - 500 µg/ml . IC50 for diethyletter and methanolic extract was 200 µg/ml in HUT-78 , IC50 for diethyletter extract was 325µg/ml and methanolic extract 325µg/ml in KB. In vitro antimicrobial activity by Broth Dilution Methods against clinical gram-positives and gram negatives (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus و subtilis Bacillus). The results conducted that the MIC values of methanol and diethyletter extract for Escherichia coli 20mg/ml, Bacillus subtilis 10mg/ml and 2mg/ml for Staphylococcus aureus. The MBC values of the diethyletter extracts for Bacillus subtilis 30 mg/ml) and S. aureus aureus 10mg/ml. In vitro antifungal activity by Broth Dilution Methods against clinical pathogens; Candida albicans and Aspergillus fumigatus. The results conducted that the aqueous extracts didn’t have any antifungal activities on pathogens, minimum inhibitor concentrations (MIC) of the diethyletter extract on C. albicans 0/75mg/ml, MFC 5 mg/ml and methanolic extract 0.5mg/ml and MFC 5 mg/ml on A. fumigatus In vitro antiviral activities by XTT assay against MT-2 cell line. The results conducted that IC50 for diethyletter extract 500µg/ml and methanolic extract 475 µg/ml
