Cystoseira corniculata and Capomenia sinuosa were collected from Gökceada shores and sodium alginate was prepared from these seaweeds. Rheological studies were carried out under conditions of varying temperature and concentration. It was found that sodium alginate from C. corniculata, shows typical preudoplastic behaviour but this was not apparent in that from C. sinuosa. Temperature has an effect on the apparent viscosity of sodium alginates from these brown seeweeds at lower rather than higher shear rates. Keywords :