The marine flora and vegetation in the small desert islands Kira Panagia and Piperi situated NNN of Alonissos, Aegean Sea, Greece were investigated in order to create a marine park for the protection of the Mediterranean Seal (Monarchus monarchus). The flora was rich with almost 110 algae species in both of the investigated stations. Seven marine plant communities were recognized, two of which belong to the sciophiles (Halimeda tuna andDilophus spiralis), and the other five to the photophiles growing in the hard rocky substrates. From the chloridic element the atlantic-subtropical are the main representatives with Sorensen index ⊥0,41, R/P ratio ⊥ 2,65 and R+C/P ⊥ 3,3,so that means subtropical character of the marine flora. Finally the amount of dry biomass in both stations was very rich and typical of this rocky, exposed and clear biotope. Therefore these small islands could probably be utilised for the creation of a marine plant park which is to become an excellent shelter for the mediterranean seal that is gradually becoming rarer in the Mediterranean.