The properties of agars from G. cf. verrucosa and P. capillacea of the Israeli Mediterranean coast, were compared. Agar was fractionated on a DEAE-Sephadex A-50 column into three main fractions: neutral agarose, sulfated agarose and sulfated galactan. Alkali treatment of both agars increased their gelling potential, by increasing the relative yield of the agarose fraction. The P. capillacea agar had a higher concentration of agarose, a higher isothermal gelling temperature and lower sulfate content as compared to G. cf. verrucosa agar.