Few studies have been done on cultivated specimens. Most descriptions are based on natural stocks collected from coastal areas and other submerged strata in the intertidal and shallow, subtidal zones (Marinho-Soriano et al., 2006). Studies on the biochemical properties of marine macroalgae in the same environment are insufficient. Although seaweeds in Thailand are extensive, they are relatively underutilized, with most of them used mainly as animal feeds and fertilizers in coastal villages (Ratana-arporn and Chirapart, 2006). In addition, knowledge about their nutritional composition is still limited (Rameshkumar et al., 2012). Therefore, this study was conducted to compare the growth rates of nine marine macroalgae under culture conditions, as well as to determine their chemical compositions such as total protein, carbohydrate, fiber, lipid and ash. The biochemical information of macroalgae will be essential for the commercial food products and health supplements industries.