We screening for antimicrobial substances production from marine algae of Syria. We presented results of ١٦ algal species tested by their lipide and aqueous extracts agaimst Gram’s negative and positive bacteria, as well as one fungous species. The lipide not aqueous extracts were the active against Gram’s positive bacteria especially. No effect founded on the fongous species. In addition we make comparative viewing with other studies on other mediterranean contries regarding the same species of algae tested.